Jaeheon Shim
Hi! I'm Jaeheon Shim, a computer programmer and technology enthusiast. Here on Learn The Technology, I write about technology and the effect it is having on our modern world. I write about a broad range of topics, ranging from 3D Printing to Cybersecurity.

Fixing A Free TV: Part 2

If you haven’t read part 1 of this series yet, I highly recommend that you do so. Otherwise, you’ll have no idea what’s going on. Part 1

So. The SC board from eBay finally arrived after a few weeks. If you were wondering how much it costs, it cost me around one hundred dollars. Fortunately, I can return the board if it does not make things better. I was excited that the board came, but I made sure to take many pictures. Here’s the new board:

Panasonic SC Board

This board looks exactly like the one that was broken. Although you can’t tell just by looking at it, this board is not shorted, while the broken one was. But nevertheless, the first thing I did was check to see if this board was shorted. You can never be too careful. This board is actually used, but you can’t really tell as it is in flawless condition. I think this board will work. So time to insert it inside the TV.

This is the TV without the SC board in it:

Panasonic TV

And now the SC board is inside the TV:

Panasonic TV

I found out that the screws used to secure the board to the frame are quite important because they ground the board to the TV. So after screwing in the many screws tightly, I attached the cable and connectors. But then while I was replacing the back cover, I got a really bad cut. Did I mention that the edges of TV covers can be very, very sharp? The cut was about a few millimeters deep and it started bleeding like crazy. It hurt too. A lot. I cut myself right in between my thumb and pointer finger. Fortunately, it didn’t leave any permanent damage. Unfortunately, I am having a hard time typing this right now. And if you think that is fake, here is my bandaged hand:

But as a lot of people say, no major job is complete without a minor injury. Always be careful with sharp objects.

Anyway, after plugging in the TV to the wall outlet, I carefully pressed the power button. And when I did, the red light turned on… and started blinking 8 times. There was no other sign of life from the TV. I was pretty disappointed at this point, so I took apart the TV to take a look at it again. And then I realized that I had made a pretty dumb mistake.

I forgot to plug in one of the ribbon cables.

This actually made me relieved, because it meant that the board was not necessarily broken. So I plugged in the cable and made sure it was tightly secured. But this time, I did not replace the cover. There are like a hundred screws in this thing and having to unscrew every single one of them every time I wanted to take a look inside would be a huge pain. So I just propped the TV on its stand and was careful not to touch any of the high voltage capacitors and accidentally kill myself.

And just as I expected, once I rebooted the TV, the fans started spinning, the relays clicked, and the screen turned on! But don’t get too excited.

Panasonic TV

There is one problem with what the screen displays: You can’t read it. This is the best picture I could get with my camera, and it doesn’t look that much better in real life. If you look really closely and try really hard to make out what it says, you can barely tell that it shows “No Signal.” The screen was also flickering, which didn’t make things better.

Another big problem is that when I tried to change the input, the TV glowed very bright and then shut itself off and started doing the 8 blinks song and dance. This literally happens every single time I try to interact with the TV, and I have to unplug the TV to fix it. I have no idea what is going on. I suspect that the TV is somehow overheating when it tries to switch inputs, but there’s no way for me to be sure.

After a few minutes of intense googling, I found out that there are two potentiometers that you have to adjust after changing the SC board. They are labeled Vsus and Vda. They are on the main power board:

Vsus and Vda

If you don’t know, potentiometers are like resistors that you can change the value of. The can be made to limit or allow more current. The problem? I have no idea what these potentiometers do. I have mentioned before, the lack of documentation on these TV’s makes it very hard and frustrating for somebody other than a Panasonic employee to repair one. So, like any reasonable person would, I aimlessly turned the potentiometers. By doing so, I found out that if you turn the Vda potentiometer far enough, the TV powers off, and starts blinking a series of 14 blinks. The TV also refuses to turn on for another 30 minutes. The potentiometers didn’t seem to produce any visible effects otherwise. So I guess there isn’t any point in messing with those.

I then thought it might be a problem with one of the connections. So I took some air in a can and sprayed air over all the ribbon cable connections. And surprisingly, that actually did something! The display showed some color, and for the first time I could make out what it was trying to tell me!

Sure, the image displayed is still terrible, but now you can see that the image has some color and contrast. But the TV still immediately turns off as soon as I try to do anything with it. I did manage to get a computer connected to it, but the quality was terrible.

This has been happening forever. Every time I feel like I am getting closer to a breakthrough, things just reset to the way they were at the beginning. The most I’ve gotten is being able to change the display settings for the TV, and the TV still turns off after a few seconds. There is something seriously messed up. I don’t know if a bridged connection is drawing a lot of current and generating heat, or if I’m supplying any current at all. And every time, the LED blinks 8 times. Maybe if I knew what that meant I could fix this.

I’m being honest: I don’t think that it is worth the time and resources to keep going forward and try to repair this TV any further. Here’s a list of all the things I did to try and fix this TV:

  • Air dust all of the connections
  • Check that all the screws are tight
  • Plug the TV into another wall outlet
  • Remove and reconnect all of the connectors
  • Remove the power boards and look at them intensely to make sure that the solder joints have not gone bad
  • Probe many, many connections for continuity
  • Check all the fuses
  • Check all of the fans
  • Clean all of the ribbon cable connectors
  • Turn potentiometers without knowing what they do

I’m not trying to sound unconfident, but I don’t think that I can fix this without buying more parts, and I don’t think that is worth the money or time. I’ve tried hard, and also made some progress, but I’ve also decided that there is a time to just stop trying. I hope that I have been able to provide a starting point and lots of information to anyone who has been trying to fix this TV, and I wish you good luck. If you have any ideas on how I could fix this problem, be sure to leave your thoughts in the comments below. I’ll try to attempt your instructions before I refund the board.

And be sure to subscribe to my blog. If you were disappointed by this article, don’t be. My next article will teach you how to make a very dangerous device that could save your life. I bet you’ll be shocked. You can subscribe using the form at the bottom of the page, or the popup message that is displayed every day. I try to make subscribing not a big feature of my website so that you can enjoy my content, but it would really mean a lot to me if you subscribed.

And this project wasn’t a complete loss. I gained a few dozen spare parts from the TV!

You may also like...

3 Responses

  1. KYU NAM SHIM says:

    Enjoyed this. Don’t cut your hand in next time. All the best.

  2. Like says:

    Like!! I blog quite often and I genuinely thank you for your information. The article has truly peaked my interest.

  3. ปั้มไลค์เพจ says:

    It is in reality a great and useful piece of info. Thanks for sharing. 🙂

Leave a Reply