Not so fast! I hit some road blocks fixing the Mac Classic

Well, hello everyone and welcome back to Adrianne's digital basement, as you can see by the Macintoshes on the bench, this is the Macintosh mini repair. Actually, we are in the second part. If you haven't seen part one, I recommend you watch it first part one I took the Macintosh SE, touched up

some

of the solder joints on the inside, cleaned it up a bit, put it back together and gave it a good test and it works absolutely perfectly, as you can see here, it's still ripped off. the Macintosh OS 6 system. Then I opened the

classic

Macintosh and currently the back is off this machine.

The motherboard was wedged there rather roughly. Turns out the motherboard has

some

leaky caps, but the power supply itself seems fine with a quick power up. The computer has no audio, but it started booting up. I didn't actually connect any dirty devices to it, but we actually had the flashing question mark, so things look good there, it just needs a good clean and a summary, so in this video I want to finish doing that summary of the Classic Macintosh and then I want to get into the Classic Macintosh 2, which we haven't even looked at or tested and hopefully we'll get that machine working as well.

At the end of this video. I hope to have three

classic

Macintoshes up and running, so without further ado let's get straight to the point, as I mentioned in the introduction, here we will focus our attention on the classic Macintosh, so let me get these other two machines off the bench so we can give it all our attention to this little thing now in case you come here looking for how to do a repair for Macintosh Classic. This machine primarily works and really just needs a rundown of the motherboard, the first thing you want to do after opening it.

It's definitely removing the neck plate from there because you don't want to accidentally hit it by disconnecting one of these cables from the motherboard and break the neck of your CRT, which would mean you would have to buy a whole new CRT, which is not easy. Nowadays, there are two common failures on this motherboard: leaking electrolytic caps on the motherboard, which 100% of these motherboards, if not already capped, will need to be capped again even if the machine is turned on and seems to work fine, those caps are going to leak so you definitely need to fix that because the longer you leave those caps there the more damage will occur to the motherboard.

The other fault that happens with these machines is leaking lids. on the power supply board there are now two large high voltage caps right here, they are not the ones that are leaking. It's usually the low voltage ones that leak and they are in this back corner, there are brown caps in the case of this power supply. and I've had several of these boards where they leak and when they leak you get this kind of brown gunk that appears on the bottom edge here and it's sticky and it smells bad and that's the electrolyte coming out of those capacitors.

This plate shows no signs. of leak and when we turn this on in the first part the machine turned on and worked apparently normally but what I want to do in this video is after I recap the motherboard I want to take out the power supply board and we are actually going to remove a couple of those lids and I'll just take a look at the bottom, if they start leaking we'll see that when we take the lids off and if they look good I'll probably put them back on. Obviously if you're going to all the effort to get this board out you could just recap it but whether that's necessary or not I couldn't say for sure but I've had several of these where those caps have leaked and therefore maybe it's a good idea to at least recap those limits because it's a known issue with these boards.

Now, this particular Mac classic came with this Ram expansion board that plugs into this slot here. I'm not 100% sure if every classic Mac came with this board or not, but if it is missing, you will be left with only 1 megabyte of memory as the maximum amount of RAM in your Macintosh when this expansion board is connected to the motherboard but You have no memory in the Sim slots. you get an additional 1 megab of RAM for a total of two and when you add two additional 1 megab Sims like the ones I have installed now you get a total of four which is the maximum amount of RAM you can have on these classic Macintosh boards that Ram The limitation, in case you were wondering, has to do with Apple's design of the original Macintosh.

All of these 16-bit and 68k based machines seem to have the same RAM limitation and that's in the glue logic that's inside this IC on this motherboard that connects the RAM to the CPU, the rest of the memory map, which is 16 megabytes total for this particular processor, it's used for things like peripheral I/O and things like that, and unfortunately it's fixed and there's no way to get over 4 megabytes on many other systems that use a 68,000 processor like the Amiga you can go up to 8 megabytes of RAM with the 68,000 based machines, once you upgrade your computer to a 32 bit processor like a 68020 or higher you will be able to add much more memory and even on the Macintosh se30. which is the successor to se, you can increase up to 8 megs of RAM on that particular computer and that is again facilitated by the glue logic that the app includes on that motherboard that allows for that large amount of memory when you look at a system like The Classic 2, which we'll look at in a moment, has a maximum RAM size of just 10 megabytes, which is definitely much less than the 6030 processor that's there allows, but again it's a limitation of the chipset that's included. the motherboard and the fact is that the classic 2 motherboard is derived from the Macintosh LC motherboard, another type of damaged Apple motherboard that also has the same 10 megab limitation anyway, turning our attention to the motherboard, Here the capacitors that have leaked are all fine. unfortunately, and if I tilt this at the right angle, you can see all this kind of goo and stuff that's on the board here and that's all the electrolyte that's leaked out.

Fortunately, the corrosion seems somewhat minimal, like if you look around the pins here. It doesn't look too bad, let's look here in The Sound area, yeah, same thing, just a mess because of the covers and these two have leaked too and it's all kind of bad and actually now that I look at it, it looks like the series. The number is actually starting to disappear and I'm guessing it's also due to electrolyte leakage, but check this out. It has corrosion down here on those two parts and the battery I don't think has leaked yet, although it might have started again.

In this area of ​​the motherboard, away from the capacitors, things definitely look better, but the caps are definitely starting to corrode and eat away at the motherboard, so this absolutely needs to be cleaned and those caps need to be removed from the motherboard. Now that we turn on. On this computer I didn't have any sound, there was no bong and I think it's this lid here that popped open, it's leaking and that's the sound boat and I'm pretty sure it's in series with the audio output that I think it's there and it also goes to this connector to go to the analog board where the amplifier for that speaker is and because this capacitor is open now it no longer passes AC which is what capacitors normally do.

They don't pass DC, they filter it but they pass AC fine because it's open, it's essentially like it's not even installed on the board and that's why we have no sound. I haven't looked at the schematics, but I have a feeling that most of these other 47s are for power rails and things like that, so what we're going to do is remove them from the board. I'm going to use exactly these needle tips here and then we'll replace them now. I'm going to take them out using the movement method better known as the Twist method. Now there is a lot of controversy about how to remove motherboard caps, but these are corroded and if you try to desolder them there is a very high chance that Unless you have very specialized tools, you are going to lift the pads off the motherboard.

I have found that the moving method especially is really good and gentle on the motherboard and doesn't remove them, but there are other methods like the cutting method. desoldering method and probably many others that you can try to use if you are going to recap your motherboard, your mileage may vary depending on how good they are, but having spoken to many people who do this type of work all the time they say that for the Casual recap , the moving method where you just move it back and forth is really one of the best and safest ways to get these caps off the board.

I first learned about this method from Ray Carlson who has a YouTube channel where he is like an expert electronics restorer going back to vintage stuff with vacuum tubes, so when I look at someone who is a real expert and who also makes a lot of videos showing his experience, I really trust that his method is good. method this is how I started doing this method there will surely be a lot of comments below about how well I ruined this motherboard or almost ruined this motherboard by doing this method and yada yada yada you know people are going to be mad and that's just how it goes with this type of videos, but I'm going to do my move method and show it and then we're going to put some new caps on this board, so as I mentioned the move method, I have these bent needle tips. which I really love for this exact use and let's get into this really messy corroded area here and what I like to do is grab one of these and I'm squeezing and pushing towards the board and you. you just start moving the lid and what you're doing is weakening the legs, you know you're causing metal fatigue in the legs and the lid just breaks off the board, it left his legs back on the pads there, which is exactly what that we want, but as you can see, this gross leaky cap here is completely removed from the dash and look at that gunk on the bottom, so the idea is that you're going to do the same thing on all the dash caps and they should all come off with Relative ease there we go, sometimes the little black thing at the bottom just breaks, which is completely normal.

I just noticed this. I just did that that was pushed, that's the clock crystal there for the real time clock 32 khz we're going to move this cap up here so again I'm pushing down and we're just moving and then we don't want to pull up you just want to do that Until it comes loose like this now normally I would recommend taking a photo of the board first so you know exactly where all the caps go for something like this board which is very common. There are many photos online. I also noticed that each cap measures 47 microfarads, except for this small microfarad cap.

I don't really need to worry about it, this lid presents a bit more difficulty with the way it refuses to come off with the movement method. Sometimes the small ones can be a problem, but I've found that if that's the problem, sometimes just Turning it a little more can help improve the situation again. I'm pushing down, oh there we go, it's out. I was pushing down and turning and there everything is fine. I'm going to stick with this method here and stop doing it. talking and I'll come back if something bad happens okay here we go the end cap just came off let's see if this left a leg behind yeah sometimes it leaves a little bit of a leg behind and what I do is you just order to use finger to bend it back and forth until it comes off none of the pads lifted or ripped everything looks good there's a lot of dirt around here it also looks really bad now I just put a paper towel under the motherboard Now what's happening?

Here's the electrolyte that's made its way everywhere, like under these chips and everything, and I found that if I just wash the board with soap and water, what happens is this electrolyte turns into salt. Don't know. I know the right name, it looks like salt, it's white and crunchy and it will be around your legs so someone mentioned to try to avoid that use a little bit of vinegar and pre-soak it and maybe rub it a little too so in here I just have regular vinegar, white vinegar, stuff you can buy at the grocery store and I'm going to pour this on the motherboard and I'm actually going to soak it in there and I'm going to do it here like Okay, all the areas where there were LEF leaks, let's go and I'm going to take a brush here and I'm really going to start working on this now.

I don't know for sure if this is I'm going to, I don't know, eat up this salt corrosion that's everywhere, what is this bubbling that's happening, is it just coming from the brushes or is it actually a reaction that's happening, I don't know. , but I'm just going to Let this get in here and anywhere where you see that the electrolyte has left a brown residue. I'm going to try to get the bristles in there and make sure the vinegar has a chance to work. It definitely seems like there's a little bit of bubbling, I don't know if that's because the bristles are rubbing against the pins, but it does seem to be bubbling a little bit, which implies that something is going on here, which is good, it doesn't.needless to say.

You had something like a Sonic Cleaner, but I don't think many people are going to have something that's big enough for a full motherboard, maybe this little Macintosh motherboard would fit in some Sonic cleaners. I actually have a large one that would fit on this motherboard, it would also fit on much larger motherboards, but I don't really want to use that because I want to do a repair here that anyone can do and something that is easily repeatable by the usual person in house, like bubbling, seems good. I like that it's kind of nice that it's bubbling like there's some reaction happening and it's actually eating up this junk that it left on the motherboard.

Yeah, I mean, look at that now, unfortunately, you may have a motherboard whose corrosion is so bad that you've eaten away traces and you have components that have actually fallen off the board. What happens with corrosion is that it can turn the solder that is used to join these components together into this horrible porous material that is very difficult to work with and B just starts to come off. In that case the boards will just have to be scraped off to try to expose some new solder underneath and it can cause your iron to use a lot of flux and just try to get that junk off the board.

Components need to be removed completely, such as small chips, you may need to try to clean them very well, unfortunately this motherboard is not that bad so there won't be any examples of that kind of work, but it can definitely happen, not to mention you can often have These traces under here start to eat away and the corrosion on this plate was definitely softer, so we don't have any traces of food, but you can often see them after cleaning them when you use a magnifying glass. You'll notice like little traces underneath that they're eaten away and you want to make sure you sort them out first before connecting new components because obviously if you connect a new component correctly you won't be able to see it. that there is an e Trace underneath once the new component is soldered back on, so you should try to fix all that before putting any components back on, so inspect things with a small magnifying glass and if necessary you can use a multim to fade out the traces that go under these components just to validate that they work before I put things in, look how much foam there is in here when I do this, yeah that's interesting, the more I shake it the more foam it forms.

I feel like this turmoil is really having some kind of effect. Well, I think what I'm going to do now is let it sit. I think I've been agitated enough. I'll let it sit for a while. A little bit, just kind of bubble here or eat all this crap, unfortunately some of the vinegar is now leaking onto my paper towel that's under the motherboard because there are holes in this motherboard, so you can continue applying it or you can just order. Leave this as it is and after this, the next step will be to wash well, the motherboard has been soaked long enough in this vinegar solution.

The next step is to take this upstairs and put it under soap and water and give it this. a thorough wash. I've talked about this method many times before, but I just take the motherboard or whatever I'm washing to the sink and use regular soap and water and one of these anti-fade brushes just to clean every corner, every time. I've used vinegar or anything else that's corrosive, I'll be sure to give it a sniff test after you're done rinsing, just to make sure there's nothing left in there now if your city has very hard water. which luckily I don't have here where I live, you might not want to let water air dry on the motherboard, I even used very high speed air from a blower motor to completely dry the motherboard and remove every trace of water .

If you're not sure about that, you can always use deionized water to rinse or even alcohol as a rinse cycle at the end just to remove excess water. Here is the classic Mac board, washed and dried, there is definitely some of that white. salt stuff that he was talking about that he was trying to get rid of with the vinegar but that didn't happen. I don't think he actually did anything, so I'm not sure vinegar is the right choice for this. I don't believe it. I don't know if this is actually corrosive or harmful in any way to the board, it is definitely not conductive.

I've had many boards like this where it has this here and there are no ill effects, the board works fine and this white stuff definitely seems to be worse in the areas that had a lot of electrolyte coming out of the leaking caps, like here around the chip. sound, but like I said, it doesn't seem to have any negative effect on the board and if you have any ideas. on how to remove this in a better way let me know but as you can see we tried vinegar and scrubbing and it didn't do anything in this case anyway the next step to recap is I need to get all these little paws off. of these pads here and clean these pads so they are nice and fresh and ready to accept new capacitors to clean these pads.

I'm going to use three things, the pine sill welder, some new solder here that I have in a little 3D. printed support and some solder wick, this is what you really need and good quality material. I'm using mg chemicals here to remove the old gunk from these pads because we want them to look nice and fresh for when we install new caps on this. Also, I'm going to use something like this to clean the tip of the soldering iron because as I pull these little pieces off the board, they're going to get stuck on the tip and you're going to have to pull them out so the method I use to remove them is to simply heat the iron to 350° and using some new solder and trying to basically scrape them off now can be a little tricky.

I'm just seeing if this works. Yeah, I think that's good, yeah, that's a good one and you just heat it up, you just add a little bit of solder and then you try to scrape it off and you can feel it when it comes out. Far. Now there we go, so it's actually on. The tip of the iron there now is going to be hard to see, I know, and it's definitely leaving a little bit of a crust on the pad, but we'll get to that in a moment, so just check everything out. of these and you just try to get those little memories off the legs of the board, there we go and this one, because it's not in two out of shape, we're doing a pretty quick job, now you notice that the solder is not sticking.

All over the pad there are parts that still have the old crusty solder like the one there and that's because the corrosion has gotten to it and we're going to have to try to clean that off using the wick and things like that. just making sure this is all smooth and now there are these kind of pads on these motherboards that are just glued on so you don't want to use too much heat or it lifts them up and potentially breaks traces and things like that. so you want to be a little quick about it, so like I said, 350°, well I guess 345 is what I'm using, it seems to work fine for me, but again, your mileage may vary.

Oops, I was doing that off camera, so just working on these and you notice there's all this black gunk coming off and again that's corrosion in effect, we're going to need to clean that up with a little alcohol, we'll do that in wait, one thing is for sure there was a real fishy smell, even though I clean this plate very well, the actual remains here are covered in that electrolytic corrosion and it's giving me a really disgusting fishy smell. Something else you may want to consider and I've talked about this in some other videos is if your motherboard has Sim sockets and they are not currently occupied.

I really recommend that you tape them because while doing this you could drop a drop of solder on your Sim socket and that will ruin your day. I, how do I know, I know because I did it and it was miserable if you drop a drop of solder in there, it's almost unrepairable, at least without changing the SIM sockets, okay, so we have the solder wick here and now. I'm going to try to clean up what we have here and get this crusty crap off the board and you can see as I move it around, maybe I should get a little closer, it leaves a lot of crusty black crap, but unfortunately that's normal. for the course, okay, here's a good example of what I was talking about.

Notice this one right here. See all this dirt there. I'm going to use these tweezers and physically scrape it because I want to. that's not in Focus stay focused I want this to be bright and pretty like the rest so there let's see what comes out the same over here I just want to scratch this I want the pad to be all a nice shine color even the part that is black and looking a little rusty or corroded, sometimes you may find that putting a little bit of 99% IPA in helps you see better because, as you can see, once the liquid is there, it gives us better visibility of what it's happening.

On the deck, now I see all this junk here that's going to come off when we try to clean it, but that pad over there I just wanted to make it a little bit brighter, so we're just trying to scrape that corroded junk off there, okay? So those two are fine, but down here you can't really reveal what's going on until you have the desoldering braid and you've gone over these, so this is the same one. Look, that black thing is here on the right side and Let's do these here and yeah, it looks pretty gross too, so let's do the same thing, but look at all this, stay focused, it focuses on my hand, so let's try to accept, there is a little.

There was a little bit of solder left there, so let's try to remove it. There is a little alcohol, but that doesn't affect it too much. Try cleaning it again. Now you will be surprised. I worked on some motherboards that were really bad and they came out great once I scratched them. I just arrived. I'm going to have to apply some new solder on this one because it's working fine, notice there when I tried to apply it just sold, it just stuck there, it didn't even stick in this whole area and that's again because there's that crap in there , that corroded weld is left behind, that's what we're trying to clean up here by scraping it off now.

This scraping that I'm doing here you really have to be careful, you don't want to scrape too much because you could damage the pad, you could peel it off, you know you can do a lot of things so I try to just scrape the pad. on itself and not off the edge and back to it, you know, I don't want to rip it off the board now, with this one you notice that there's a little bit of exposed copper there, that's because that was the trace that went from that via to the pad It had solder strength, but it came off and that's because the corrosion actually weakened the solder mask and that's what's happening now unfortunately.

I didn't mention this from the beginning, but if you get something like cotton swabs that can help you. We're going to clean up all that dirt that's left behind so you can see a little more clearly what's going on underneath, so this is going to look a million times better than it was and if we go up to this area and erase that as well. and now these pads here are all nice and clean and ready to accept. I'm going to clean up a little bit down here, they are ready to accept new capacitors. Yes, what an improvement.

Sometimes I find that the alcohol helps clean up that junk left over from the electrolyte leak. Well, the next step is these covers here and I'm going to do a time lapse, so check it out. Ward looks a lot better now, doesn't he? I did some cleaning around these ICs to try to remove that white salt and now all the pads are looking really shiny and good and we are ready to connect some new capacitors to this board to replace the caps that this particular board uses. 47 microfarads. I think the originals were 16 volts, so 16 volts or 25 volts will be totally fine and it used 1 microfarad and I don't remember what the original voltage value was, but this 50 volt part here will be fine now, unfortunately.

I only have one of these in this bag, so I'm going to use these caps that are 47 microfarads and 16 volts, but now they're ceramic type. They are always a perfect replacement for the caps that were here and that's because of the capacitance. The values ​​of these ceramics are very voltage dependent and these could end up being something like 4 microfarads instead of 47 because they won't always run at 16 volts, many of them will run at 5 volts. here, so keep this in mind when choosing spare parts. I found that these ceramics work very well on these motherboards and don't seem to cause any negative effects, but could possibly cause an effect, especially if used as a reset circuit or something. type of time based circuit, the capacitance value is much more important in them, also if you had 100 microf versions of these you could use them instead of the 47 just because of that voltage dependent issue, but that's it What I like about these ceramic caps is that they are non-polarized, so you don't have to worry about polarity when installing them on the board.

Fortunately, Apple is very good at marking. the correct polarity, some manufacturers like Commodore sometimes make mistakes and if you follow the markings on the motherboard, it willThey may install a couple of covers incorrectly and those are specifically. I think the Amiga 4000 has that problem, so we have our seven caps here for the 47 and I'm going to grab one of these microfarads for the audio circuit here and what this tells me is that I need to place an order for a Digi Key to Get more of these caps to have more options available for future recaps. Okay, next step is Rosin Flux.

Now I like to use Rosin Flux. Also, I don't use clean flux, what I like to do is take this rosin flux that I have in this dropper bottle. I just put a little bit between the two pads and this helps me put the lid on a little easier. If you're not familiar with flux it helps the solder flow through the connections now we're looking at solders like this it's actually a rosin core so it has flux built in but it's only exposed to the component once which melts the solder when you have something on the board like this and you take one of these capacitors and we just put it in there, so the flux is now stuck in my tweezers but it's also stuck in the piece that holds the piece on the board and then, as soon as we apply new solder, it actually starts to flow around the component, which is perfect, it's exactly what we want, so what we're going to do is we're just going to apply some new solder to the tip of the iron here and just I'm going to use some tweezers to hold the piece in position and I'm going to heat this up.

Oops and then it flew away. Okay, so I attached one of the sides, I didn't have enough solder, but I'll go back and apply more once I've gone through and placed all of this on the board on at least one side. The other benefit of these particular types of lids, these ceramic ones, is that they don't leak, there won't be any leaks in the future. These caps can shorten their failure mode and is also very similar to tantalums, but usually comes from a stress fracture in the piece itself and not just over time. Now some people have OCD regarding component alignment.

Personally, I'm not. I just put them there so they are on properly and not shorted to anything else that is nearby, so those four caps are now attached only on one side and not with enough solder, so what I like to do is just flip them over the board. because I'm right-handed, I'm going to use my right hand here and we're just going to apply solder and heat and attach the other side to the board tight with a little fillet there, whatever it's called, and there As you can see, now they're securely

fast

ened on the other side, so I'm going to turn it over and then clean up the improper soldering that I made on this side.

Here and there we go, there's a little bit of flux residue there. That's what the brown stuff is, but it's all very tightly adhered to the board, and all that's left is this little microfarad cap. Here I'm going to use this same type of cap that was there, a small aluminum radial or whatever. This is called and my tweezers are too sticky so with that flux applied it's exactly the same, you just hold this in position and solder one leg first as long as the cap is fine, sorry it was probably out of focus. but now it is attached with one side not very well, but well enough to keep it in place, flip the board over.

I'm going to hold the lid again and we're going to touch the pad and the leg together like this, now it's there. attached on both sides and I'm just going to use the actual solder here to get more there. I want to see a little round bead or something like that, that's where it holds the leg to the board and now with this flipped over the same thing on this side there we go, the little round thing that holds that lid in place, by the way, you see the sign positive there that is far from the black mark.

That's right here, that would be the negative side and you're also square on that side and the little black plastic thing on the bottom of the lid that I should have shown before has angled corners since the silkscreen markings are on the boards, which helps you target that particular part there, now we can try to clean up. a little bit of this a little bit if you want, so just use a little bit of IPA and you can use a cotton swab or something like that to try to remove some of that flux. I mean, it's completely optional.

The flux is not corrosive, it is not bad for the board. it's a bit unsightly so clean it optionally if you want to be honest half the time I don't even bother, also make sure while cleaning that you haven't bridged any glasses close to joining with some extra solder so you just want to go back to check that everything looks good. I think things look pretty good on the board, though at least in that area and I see a little bit of lint here, so we'll do the same thing, just clean this up. just a little incidentally, the other type of cap you could use when remaking these boards are tantalum and that's one over there, this black one, why didn't Apple use these everywhere?

Who knows that these types of tapas here are cheaper, so me? I assume this was a cost cutting measure. I don't know, some of the early Mac 2C and Macintosh 2 boards were all tantalum and were very expensive computers, so I guess yeah, it was just cost cutting if they had used them. There's a good chance there's no damage to any of these boards and all we might have are a few shorted plugs here or there, which isn't a big deal, so there we have it, it's a classic Macintosh motherboard recapped which you might want to check. on the back, make sure there's no corrosion or anything that's in here.

You can sometimes get blue, squishy stuff from electrolytes that have leaked out of these leaky caps, but no, there's nothing here and you may want to double check that you have the correct polarity on all caps. If you are using polarized caps of course in our case we only use this one here and I know one is wrong and the rest don't matter because they are not polarized so this is done right so the analog board or the source board The power supply here has exactly the same little plastic clips that it had on the Mac SE.

We need to work on this area down here, which is going to be hard for me to get my hand in there to try to pull those. Take the caps off and put them back on so I think we're going to take this whole board out of the box and I want to see if we can do it without unplugging the high voltage anode cap so if you're doing this you can just skip touching all of this high voltage part and then, um, feel a little more confident about things to remove this from the case. There appears to be only one screw here.

Does this come out? No, because there's another screw right there. It was like hidden behind the metal chassis. I couldn't see it. Now I think this thing is totally free. In fact it is and as you can see this zooms out and I'm doing it in a way that leaves everything. the wires attached except the neck here because we don't want to potentially break it so leave it out and then you can just get this out of the way let's get these little clips out of here so you can remove this plastic and this is where this little bent spike comes in very handy because It allows us to remove them with relative ease.

Well, that was the one with the speaker, so we're getting there. Okay, so everyone here is off. that allows us to peel this completely and take a look at this that right there there is electrolyte coming out of the caps that is not flux residue that right there there are leaking caps there is also something right here that somehow makes its way through the dash a little more So yeah, this is a leaky lid area. I didn't think it was, but it absolutely is. What I find very interesting is that, as I mentioned, these are good brand caps, but I have power supplies that have never been used like new.

Old Apple repair parts. I took them out of their bag, they were sealed there and leaking, so it seems that back in the early 90's or mid 90's when these power supplies were manufactured, those caps had become trash. I've never opened a Mac SE and seen leaky lids like this, but on Mac Classics it's normal and seems very common now I attached my jaw back to this piece of plastic to keep it out of the way and you don't have to take those last two clips off Now, you can take them out just by using a desoldering braid like that, but I'm going to use my desoldering arm because I have that thing and it makes this process a lot easier, but if you don't have one, all you need to do is hold those caps on one by one. one and just heat up the legs, pull them off the board, you might want to use this braid to clean it up and then you can just pull them out, okay.

I've removed all the caps that you can see down here, it's a big mess, there's a lot of electrolyte leaks there now when it comes to the rest of the caps on the board here, like see these blue ones and the black ones there, those are well the only ones that are a problem are the brown ones that were in that area and those are on the five and 12 volt rails on the power supply output, let's plug this in here just to make a little more visibility, but you see all those leaks there, yeah, not good, but these things down here are fine, it's just these caps that are the problem.

Now looking at these lids you can see there is a leaky mess, now it could be this two and that. one over there with the black plug, these could be really good, maybe it's really hard to tell because everything is wet. I have a feeling it's these caps here SXF that are like the serial number, let's look at this one here, so this niche C here is a different type PL I think I wish it was on Focus, there's PL, so maybe Maybe these are okay, it doesn't really look good, does it? I'm going to say that that one is leaky too and then this one definitely is. a squirt definitely a squirt here and yeah okay so there was another one here that I dropped I think it was a squirt oh there's two down here actually okay so this one here is one of those PLM ones that I'm not sure.

If this is actually leaking and then there's another little one down here that fell out while I was desoldering and it's one of the rubber plugs, no, this is also a PLM model, they all look pretty bad and you know. What happens now that these are out of here? It smells, it smells very fishy and it's horrible, so what needs to happen now is the plate on this side needs to be cleaned of all that ELC electrolyte leakage. Now one of the problems is that this can leak and go up to the voltage regulator, and if I try to move these wires out of the way, it's this IC right here and when the electrolyte gets there, it's kind of a high precision part, it starts You're going to get weird voltage outputs from your power supply, so I really need to spray a lot of alcohol on this area and just clear this out of all this junk.

Now you have to be careful, this speaker is riveted here and you know that putting too much alcohol on the area could damage it and also. there's the transformer for the flyback switching mode power supply, so what I'm going to do is I'm going to grab some paper towels here and I'm going to fold this up and stick it there so actually, you know we can unplug this. cable here this is the return fly or sorry this is the deviation bud here and that should give us a little better visibility there we go so I have my 100% IPA it's in a spray bottle well it wasn't originally , but just um I just put a spray nozzle on it and then we'll start soaking the area here.

Try to clean up all that junk that leaked all over the board. You want to make sure you clean the area around that IC right there, just to be nice though. of throwing that out and wow you can see how much junk is on the board right there, look at this, what a mess, grabbing some of these cotton swabs may help just to soak up the roughness, look at that, so while I'm personally not a big fan of general recap tables. I'm also a fan of changing caps that are known to leak and on Mac Classics, these ones here, these brown caps that I took off, they're problems, they're always problems, now what?

I'm also cleaning up the edge of the dash here and removing all that stuff that was visible on the back where when we lifted up that plastic guard and just looked down here, things looked pretty good, this thing doesn't leak a lot so it doesn't. I see a lot of stuff around the IC chip there, the voltage regulator, but I've had a lot of these boards that, when the shit is there, they're kind of conductive and then what? What happens is the machine doesn't regulate and you end up with like four volts on the 5 volt rail and weird things happen in this mess down here.

I guess my paper towel wasn't really in the right place to catch all that junk. One thing I just realized I didn't do is that I didn't pay attention to where these caps were on the board. Sorry, it's a little out of focus. You really want to make a little map first of the polarity and how they install. For my luck. I have another one of these power supply boards on hand. I'm going to go look at it and copy the values ​​that I get from that board so we can populate it again. I don't have these exact covers.

I'm pretty sure I don't have these exact caps withthe sizes and the skinny versions of these, but I'll find something to make this work well, so this is my other board that I just grabbed now this thing had like physical damage you can see there's like a bunch of pieces removed because, yeah, stuff, wow, this thing broke, but these are the original lids and the interesting thing is that they don't leak, but I was just looking at them and I can something like that. See why they are nichens again, but they are different series. the ones that leaked that were sfx series are lxf and that is lxf, that is They are on this board, the values ​​are the same, but apparently they have a slightly different series, so I have a feeling this board is older and maybe the caps they used were better quality, maybe these changed to a plant of different manufacture and that's what happens, but I don't know, like I said, I've had a few of these classic boards. the caps never leak and I have others that are guaranteed to leak anyway, at least with this board I can now see the values ​​of things and which way the polarity is on them so I'm going to look for replacements these, just see what I have in stock and then we'll reinstall some parts on this board, okay, checking my stock.

I have these two caps, a good replacement for these. I have a good replacement for these two, so those two, but I'm missing these two, I'm just going to steal them from this board and we're just going to reuse these old caps. I know that's not ideal because I don't want to put potentially leaky lids on this. Well, but well, this hasn't leaked and I don't think it will because they are slightly different caps and at least these other two are good brand replacements, now we might find that when we remove them, they are also leaking and in that case I'm going going through my parts to find something else to put in place of these caps, so this one here I need to change it first, it's 470 volts and the negative rail is facing this bar here.

Okay, so this one is good, no leaks and in good condition. Excellent. Okay, so the 470 that was leaking here is installed, so we'll throw it in there. This is the 2200 at 16 volts, which is this cap here. Fortunately, this is one of those LXFs that hopefully won't leak again. The negative rail faces this bar here and if you're going to desolder them, it's actually good if you do it the other way around because they can just fall off. board that is useful like the one you just saw just fell down to this cover. It would make the camera focus, it doesn't leak either.

Cap lxf to win. Okay, what's happening now. I'm changing this here. It's just that the corrosion that's in here just makes it very difficult to re-solder that cap that I was trying to put on, so even though a lot of alcohol was put in this area, that's what this white stuff is, I'm going to use my pliers. again to do the Same thing I did on the motherboard and just scraped where the solder goes just to help it stick a little bit so let's see if that helped a little bit here yeah I noticed that now it's actually stuck to the plate correctly, so that's good, what about this side?

Yeah, that side is better too, so I'm going to stop the camera because it's just a matter of reinstalling the new caps on this board and using the other board as a reference. Well, the caps are reinstalled, aren't they? It's the nicest thing in the world, but you know, this should work without a problem, now you might have worse corrosion than this board has. To be honest this is pretty minor, if you start to see traces that are eating away you should scrape them off and then add some wires to reinforce that, but this looks good.

I don't see anything missing and we know this power supply is working because we actually turned it on briefly and it worked, but those leaky caps are absolutely It would have been a problem in the order for sure if we didn't change them now. I just noticed that this cap here is a 50 volt 220 microfarad SXF version, so I don't really trust that because it's the exact same series as all the ones that did leak, so I think I'm going to proactively change them and look around, the rest are all blue, they're probably fine, so it's just that brown that I don't trust as far as I can throw it.

I'm going to steal the cover off this board because I don't have it on hand and the way I just got it off the board is I heated one leg, bent it and then heated the other leg and it came out. I should have paid attention to how it's installed, oh the other board is still installed so I can look at it and see if this one is leaking. Let's see if I have another hat I can use instead of this one. I just noticed that I have these kind of no-name caps here 470 to 50 that would have been one of the ones I stole from the other dead board to put on this one, so I could have used them, but at least I put brand name caps on, although I didn't feel good by putting those potentially junk caps on this board so the one I removed is 50 volt 220 and look at this Sano brand 220 50 volt.

We are talking about a smaller package. We will use this one. I don't know where I got this one, but it was clearly never installed on a board. Well, I installed that Sano cap right there on the board. These are the two that turned out well. one from this board, one from the other board and neither are leaking and although these are the single caps, neither are leaking so I don't know, maybe none of the ones with the black plugs here are actually leaking. Some like this, wow, they sure look like they're leaking, but maybe the ones that actually leaked are the ones with that PCB looking plug instead of the black rubber one.

I think that might be the case, because if you look at the legs. On the one on the left you can see that the legs are corroded, but the ones with the black plug were not corroded while I was there. I also changed this cap, that's the 470 at 50 volts which was the one I took from the other one. Dashboard I ended up putting the uh, that nameless one I had in stock on the dash, so now there's just one old cap here, it's this one here, the one I took off the other dash but it didn't leak and it was a different series than the one. the one that was originally on this board so I think it should be fine, everything is falling apart so I think this board is ready to be put back together.

I think I've cleaned it up enough, so I'm just going to reassemble everything here. I'm sure you reconnect the fan and all these connectors and the little plugs and you know all that. Okay, the power board is back on now. I just need to find what I did with the motherboard. Here it is, it was on the ground. Yes, it's all ready to go now, of course, I didn't test the drive or check it. It is exactly the same as the Mac SE. I'm just not going to bother with this particular video because of course I have a separate video about it.

I'm just going to use this blue scuzzy for testing because this thing works and it's a lot easier than trying to boot disks into these things so the analog board connection from the power supply to the motherboard reconnects. I'm going to plug this in. the floppy drive cable, let's put the neck board back in here, so I didn't unplug anything else here except a few things on the analog board, but I put them back in when I plugged this back in and screwed it up. here is the ram card that i installed the memory in, the jumper here says Sim installed or Sim not installed ok The Sims are installed now so I move it to the correct position, this just slides into this slot here and down on the motherboard like So before I plug in the blue scuzzy, I'm going to check the voltages with the multimeter here once we turn this on because now that we've got it summed up I don't think that's going to cause anything, but the fact is that the electrolyte It was all leaking all over the board and could cause the voltages to be a little high or low.

Now there is a potentiometer that is difficult to access. It's below to adjust those voltage rails, but there is an adjustment, so let's go first. To start with the 5vt rail, we make sure it's off and we plug it in like this and here we go, actually, I'm just going to change the range on this so it doesn't have to Auto Range on there. wow it's much

fast

er at displaying the voltage, here we go ah we have no sound we have a system that is not working at least the voltages look good ok you have an unhappy Mac on the screen so it turned on but it worked correctly. to Mac unhappy, let's get the RAM card out of here and I'll try again, okay, we've got a good sound in there, so it's a good 5 volts, so it's great, let's change this to the 12 volt rail, we'll just make sure. that looks good 11.95 so excellent our voltages are working well and let's take a look at what this looks like on the front now as before it's a little squashed but the image is stable it's working and everything looks great now I'm wondering what Continuing with this now, the RAM that I installed here I didn't even test it, I just put it here, so I'm going to remove it, turn off this machine first and I will find another memory that is tested now. like on the macse these are super fragile Sim slots so I'm just using a tool so I don't extend the little clip too much, there let's get them out of there.

We have 80 non-standard Sim data installed now Sim not installed, yes, Sim installed the jumper is in the right place I think I'm just going to put the memory card in the machine, okay, the memory card is installed, let's turn it back on this Wow, unhappy Mac again. I'm pretty sure that's what's going on here, yeah, so. it says all zeros and a five and then the next line is 000080 that's unusual let's turn this off and yes the computer works fine without it let's get these modules out of here how about without sims installed there is no corrosion of any kind on this plate?

It doesn't have capital letters it just has a tantel here that didn't leak well, that's back in oh unhappy Mac immediately again fascinating. I haven't run into this particular issue before, that's fine and I just changed it to the other Sim Jumper setup installed when we don't have any Sims installed and we're getting all this now. I think this is happening because it might be trying to use the top of the memory where the Sims are not installed for video memory which is why this is happening. because the data line is floating because the memory is not even installed on the board, so if we take out this board it will work fine again, that's it, yeah, there we go, so there are two possible problems with using this Ram card in this Mac.

Is the motherboard at fault or the card, it's an interesting problem so I think the best thing I can do is try a different card, so I looked through my stock here and found another one of these cards, let's see how it works here. First let's test this card without additional RAM installed, let's see what it does, so we have a motherboard failure. Well, that's interesting, very interesting. We have exactly the same error code on the screen. Well, well, things. Suddenly it got kind of interesting, since we have two cards that don't work, we know for sure that it's the motherboard, so let's get that thing out of there and start inspecting for traces of broken, but actually, before we dive into In-depth troubleshooting on classic Mac. motherboard something I didn't even think we were going to have to do, let's take a look at this, this is the Macintosh classic 2, wow, all shaky, let's open this up, take a look inside and then turn it on and see if it works. because I honestly thought I was going to end up with both machines in this video and, well, the classic through a curveball and who knows what we're going to find inside this thing, so let's take a quick look at this, ah, the Macintosh . classic 2, as I mentioned earlier, this is derived from the LC, the low-cost Macintosh LC, which was one of Apple's best-selling machines, at least at the time, because the original Macintosh 2 line, the Max color, was very expensive, so when the LC came out, people were excited that they could buy a color machine that was really cheap but had a lot of limitations, had a lot of performance implications and when you looked at the specs and saw it had a 68020 at 16 mahz, you thought it would be cool. fast machine, but no, because Apple didn't want the LC to break into the market of the fastest Macintosh machines that were on the market at the same time they gave that 32-bit processor a 16-bit data bus, which it slowed it down drastically, they also gave it like a really funky low resolution color screen and when the Macintosh classic 2 was designed, they took that weird broken motherboard from the LC that has a limit of 10 megab of RAM which is crazy for a 32-bit processor, and they put it in this. the color display capabilities and the expandability because it had an expansion slot in the LC and by inserting it into this thing with the exact same limitations, they even upgraded the processor to a 68030 but with the same 16 MHz data bus and 10 MB memory limit. well it's quite disappointing compared to the se30 and this machine was supposed to replace the se30 it was a lotCheaper but runs maybe 30% slower than the se30 at the same clock speed, the sc30 can reach up to 128 megs of RAM.

It includes a built-in flat floating point unit, so a math code processor, and it has an expansion slot, everything this thing doesn't have. It's technically possible to add an FP or a floating point unit to this, but I think it doesn't make sense. really do anything, except maybe some weird app that actually uses it, um, let's take a look at this, it's actually just a classic case, like I mentioned this case, um, wow, this is weird, oh, this is like if it should have some type of sticky adhesive. a copy is in it as I mentioned the Classic 2 and Classic share the same case.

Later, Classic 2OS has holes here to allow audio from the speaker to pass through the case a bit. For some reason, this one doesn't have it. It says Classic 2 here on the back. The serial number label is almost worn off and then the only add-on this thing has over the classic is the audio input here, the classic just has a solid piece of plastic there and it has audio input so if you're going to put a classic 2 on a classic motherboard, the only thing you have to do is unsolder this audio input jack from the board because if you try to attach the case when it is still installed it just won't work, you can also just drill a hole. the back case on the classic Mac and then I have access to that port, but I actually have one of these two classic stealth ones that I like to call them and I just desoldered that Jack, I just tied it inside the case, so if I ever want have that again, you could do that now as for disassembly, it looks like this case doesn't have any screws there, how about here at the top?

No, and that one isn't installed either, so none of the screws are installed. Oh, by the way, check out this look. On this, there must be something written here and someone didn't want that, so they sharpened it and then put a non-yellowing sticker on it. Now the way I like to remove this case is, you know, if you try. It doesn't really come off, so I use the method of violence, there we go okay, on first appearance, you can tell by the amount of soot on everything here, it's dusty, but it's also very likely that this thing has been used a lot more than that classic or the SE before that, so there's a good chance this is a little worn.

The first thing we need to do, of course, is remove the neck plate and let's take these cables off the motherboard here and we can take a look at the beginning. the battery hasn't leaked it's not that great it's absolutely great so this machine supports a total of 10 megabytes of RAM it has 4 megabytes on the motherboard which is here and then you can add an additional 4 megabytes of Sims here to that total. out of 10 is our 68030 processor clocked at 16 MHz, we have a bunch of ROMs there, a dirty floppy disk, it's more or less the same as the normal classic and look there, you can see that the juice from the cap has leaked everywhere and it has made everything sticky.

It doesn't look totally horrible, but it also doesn't look very good now for the power supply board, there are actually two different versions, there is a later version with a reduced cost that has an even higher cost and which was mainly found in the two classics and this is not one of them, this appears to be the identical board we just worked on. I'm going to assume it will have the same leak we had on the last board, and we are peeling the plastic here, yes, we have corrosion here. Also this leaked exactly the same way as the other one and looking down at the board they are the exact same terrible Nichon caps and they look very sticky and gross all over the place, now what I want to do now is on actually just put.

Put the motherboard back in and let's turn this thing on and see if it shows any signs of life. I noticed that whoever took the hard drive out of this at least put the hard drive holder back in place unlike the classic one, that's a positive just for Curiosity, this battery is minus 0.02 volts. Wow, negative voltage same as the other one, okay, mains is connected, let's see if this lights up, we're not going to have any sound, I guarantee it, but let's see if we can at least make it. The blinking question mark no, it was making a terrible noise like it was coming out of the power supply so yeah I think the power supply is not working and I'm sure it's because of all that electrolyte and whatever is in it her, but all is not lost. like we're dead in the water and we can't test this motherboard because all I have to do is take this motherboard out and then put it in the classic Macintosh, so here's the classic with the motherboard not working properly, I want say.

It works, but it's not with the additional RAM, so the classic 2 defective motherboard covers come in and everything, let's just connect this plug to the cables. I'll even plug in the floppy drive, why not? Okay, power's on, here we all go. True, there is no sound, it is as expected. Hopefully we'll at least get something on screen. Many of these machines may not work. When the caps are bad, you get good, you don't get anything good, so yeah, we have a working power supply though. The motherboard is not happy, well I was hoping that we would have validation that this classic 2 motherboard was functional, so before I go ahead and summarize it, I know we were going to have a functional motherboard, but I guess in the case of the classic we recapitulate it. and we didn't get a working motherboard, we got a mostly working motherboard and in the case of this one it's a mystery and with that bombshell, I'm going to have to end this video here as I suspected at the beginning of the series.

Macintosh Classics live up to their reputation for being unreliable and it all comes down to the capacitors on the motherboards and power supplies. Now hopefully this one will work after summarizing it. I don't see any serious corrosion here, which means it should hopefully work. I mean, we're not getting any signs of life right now, so that's not great, but I've had plenty of motherboards that didn't work at all and then after summarizing them, they worked completely normally on the other ones. By the way, this motherboard, the classic motherboard has now been expertly recapped by me, looks very clean.

I mean, look, this looks new now with all the new caps and yet we still have the problem with that Ram card, so that's where we are. I'm going to delve into part three to try to figure this out and probably also between now and part three I'm just going to recap classic 2 off camera. I'll fix the power supply and then replace the caps on this. I think I'm going to have to order some covers to do this, it's essentially an identical job to what we just did on classic 2 or classic, I mean, so I'm not going to bother showing it, but I will.

What I do is save the first power up for part three so we can see together if this works or not and I guess at that point we will know if there will be a part four where I hope to be able to fix this classic and if I can, in part four , if this doesn't work, we will have to investigate what is wrong with this problem. We are starting to enter some very difficult territory to solve and that is due to a large part of the logic of these motherboards. It's all combined in these vsi chips here, so if you have problems that exist there, that's not just a bad trace or something, you're in a bind with these anyway, I think that will be so, so I hope that you have enjoyed.

I hope people found this video helpful on how I go ahead and summarize these particular machines. I wanted to show that, especially with the power supply, I don't really recommend a general overview of everything that's there. There were many tapas that we had. I didn't touch just focus on the bad ones and it's always those brown ones that are the problem so take care of the ones on your classic even if you haven't before. I recommend you do it CU, it probably will. it will eventually leak and then combined with the recapped motherboard you should have a nice long lasting, hopefully reliable Macintosh machine, so if you are looking for one of these machines you are better off avoiding these things, actually just avoid them and get a Macintosh SE. or a Mac Plus or something, unfortunately the se30 also has a very bad capacitor plague on the motherboard, so it will need help, at least the rest of the Macintosh sc30 is reliable, you just have to double me with these things that's why what I'm saying yeah stay away anyway hope you enjoyed this if you give a thumbs up to all that usual youtube crap thanks to my sponsors their names are next to the screen they get early access to the videos , all that, there's a link in the description below the description below if you want to become a patron, I think that'll be it, so stay healthy, stay safe, stay safe and see you next time, bye.