I fixed a broken 4K 55” TV with TAPE | How to fix a TV with a blank screen

This is a

broken

55 inch 4k TV that was considered beyond repair but I'm going to fix it with a piece of

tape

. Someone posted this TV for free in a local Facebook group and when you turn it on you don't get any pictures. In reality, everything was so new that it was under warranty. Their repair guy couldn't figure it out so they got a replacement and got rid of it. People get rid of useful and valuable things all the time and those things can be repaired in a My hope with this channel is to help you and give you confidence to fix something or learn something new and save money, so let me guide you through the process how I got this TV, how to locate the problem and I'll explain how.

A thing as simple as a

tape

can fix an irreparable television. The guy who gave this TV away was great and he was very eager to see if he could fix it. His new TV was already there, so it was fun, he was supporting me. Here it is. What happens when you turn on the TV? You probably can't see it in this image. The backlight turns on but there is no image. If it had sound on, you would hear sound. The owner told me that the image became darker and finally appeared. there was no picture, he said that the TV technician replaced the main board and t-con board, but he still didn't know what was wrong, based on that information, I have an initial guess of the problem, it definitely sounds like a challenge as long as it is I have a

broken

television like this.

I follow a process to make an educated guess about the problem before pulling out the screwdriver. I've repaired a lot of TVs over the years, in case you're interested in learning some of those steps. I have prepared a free 26 page pdf of my best diagnostic tips before buying a screwdriver. You can find it in the video description link below or on my website frugal pair comm under the resources tab. Now I searched online with this model number and didn't find any. Common Problems I know there is backlight but there is no image and it's time to remove the back cover and perform some more diagnostic steps.

This is the TV with the back cover removed. It's backwards. You can see that there are not too many pieces. Here are three. Main parts there are power supply, T-con board and main board. The original owner told me that the repair guy replaced the t-con board and the main board around here and still couldn't figure it out. My first guess is that the repair technician did not really replace the t-con board or the t-con board has a fault or it is more likely that there is a problem with the LCD panel, so the first thing I will do is a quick check with my thermal imaging camera to see if I notice any short circuits on the t-con board.

This thing is very good and it clips to my phone. It's a little pricey but I use it all the time for things like this, finding cold spots in the house or even checking the kids temperature, check out the video description in case you want to see what I'm using. A spot that is unusually hotter than others on a board may be an indication of a short circuit. This is where there is an abnormal amount of current in a component and that extra electrical current shows up as heat. Now that I see this, it's hard to tell since some of these chips would normally run hot or run hot compared to others, but I don't see anything that seems abnormal to me here, so I'll move on to what I think was the problem. first of all, and by the way, I'm going to do a two-part video series.

In fact, I am also working on a TV with horizontal line damage and there is a solution. similar to what I'm looking for in this TV, so if you want to know more about the details of what the tape is going to do to fix a TV with an LCD problem, then be sure to watch the video below or me. Plan to dig deeper and make sure you get all the notifications. Click the bell icon at the bottom right so you don't miss the next video when it comes out, so this next diagnostic step is easy and very important when tracking down an LCD problem, there are usually two ribbon cables coming out of the board t-con that control each half of the

screen

.

The best thing is you can unplug one of these at a time to see which side has the problem so I have the right side cable unplugged and I turned the TV over and plugged it back in and I'll turn it on and see what we get oh great, that's a lot more than what I was getting before this tells me that the left side of the

screen

is fine and the problem is on the right side of the screen, so what I'm going to do is unplug the TV and reverse the process to see what happens and confirm that the problem is on that right side.

I will reconnect the ribbon cable that connects the right side of the screen and disconnect the other. I'll turn the TV over and see what happens. Okay, it looks normal, but I see some lines on the screen and that funky green stuff is definitely not normal. Oops, there is a problem with this TV. I would expect the left side to stay solid white, but since it's black on the right side and those weird things happen on the left side, that gives me a clue that there is a problem with the signage on this LCD panel, so although I suspect the problem is inside the panel, I'll still want to check the controller board that is under this metal bracket for shorts.

I'm testing the capacitors along the edge for shorts to ground. I can't find any, so let me come out to the t-con dashboard and show you where I'm going to look next to try to isolate the problem. The function of the t-con board is to help coordinate this complicated signage that you need. To match the image data to the on/off of individual pixels, the image is placed on an LCD screen, one row at a time, and it happened so fast that your eyes don't even notice it. The important thing for this process is what is called a clock signal and there are clock signals that go to both halves of the screen, which is important to know and if you look here on the right side of the board where the problem is, there are labels that they abbreviate the clock with a CK or sometimes there is a CLK and notice there are eight of them, they correspond to the signal lines that go to the connector, these are the signals that I am going to block on the ribbon cable using tape and then I'm going to unlock them one at a time to find which of these lines is the culprit, so with a small piece of tape next to the ribbon cable, I know from the print on the t-con board that pin 1 is something I don't know about .

I have to worry because I follow those little traces to two pins from 2 to 9 and these are the clock signals that I need to block and with a rising exact knife it's not very difficult, so starting at pin number 2 I need to count to 1. 2 3 4 5 6 7 8 and I'm going to cut right there and end up with a piece of tape that perfectly blocks these eight clock signals so that the ribbon cable goes back in and this is the first test of whether this will work. This is very funny. Let's see, turning on the TV, let's see what we get.

Wow, look at that whole picture, but I don't know if you could see it. There were a lot of lines on the screen. Don't know. that shows up on the camera uh-uh I could see a lot of horizontal lines there, they're not perfect, but we're moving in the right direction with the camera closer, you can see the horizontal lines and they definitely affect the quality of the image. Here is a target. Image of the screen and you can see the lines very clearly, but this is certainly a progress from the dying green screen of before. Well, now I need to do a little trial and error.

I'm going to unlock one line at a time and place the tape. Cable back into the TV. I expect the picture quality to improve overall, but what I'm really looking for when testing each line is for the problem on the TV to get worse, which helps me figure out which of these lines to watch. This is the problem, so here is the screen with watch line one unlocked. Maybe it's a little better overall, but you can still see the lines and it doesn't look good, so let's go ahead and go back to the artboard to cut another piece of tape and unlock lines 1 and 2 and see how it looks, It looks a little better than before, but those lines are still there, so let's move on to the next one and I do this a few more times.

I don't see any major changes after unlocking the lines. From 1 to 5, those lines on the screen are still visible, but when I get to unlock line 6, something very interesting happens. Well, here we go, lines 1 to 6 are unlocked and oh, I finally see something different, the lines look more prominent and you. I can start to see the screen go dark there, which means that whatever is connected to line 6 of the watch is almost certainly shorted and is significantly ruining the image quality. You see, it's causing this downward spiral with image quality. We have found the culprit here.

I won't bother trying lines 7 and 8 since I'm 99% sure I've discovered the main problem, so I'll just block line 6 and hope this gets

fixed

. please fix the problem and get me a good image again. I'm going to explain a little more detail of what's happening here in the next video, so stay tuned, ok, here we go. Line 6 is blocked out, it looks amazing, that's the best image I've seen so far the lines are no longer there and I don't really see any other imperfections on the screen so let me go to the test screen and we'll compare here .

You can see the letters from before, but this time there. There are no lines after looking at the TV, the only thing I found was this faint line on the top right that is really only noticeable when there is a white image on the screen. Well this is really interesting with my macro lens on. I can see the individual red. green and blue subpixels that make up the colors of the image. This is looking at the top speed of the screen. Look at which line has the problem. Yes, if you count backwards you can see 1 2 3 4 5 and the problem is in the row of pixels. number 6, then this probably means that there is a short circuit in one of the subpixels in row 6 and by blocking that clock line I didn't solve the underlying problem, but it did solve the symptom and you can see that the TV is working very well.

This is an amazing 4k image and you can't even see the line at the top when you're viewing it. Let me know your thoughts and questions below. I'd love to hear from you if you want to see more of what's going on. behind the scenes join me on Instagram and before I go here I want to thank my daughter who designed this new t-shirt ready for me thank you honey if you like repair videos check out my repair playlist here while we are waiting for the second part to be published.