Plasma TV repair attempt - Vertical colored lines & lots of tobacco
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I got this TV for cheap since it was sold as defective. It was claimed by the seller to be clicking when trying to turn it on, which it indeed was. This was easily solved by just replacing a capacitor in the power supply. However, once I got it to power up, I noticed that there were colored vertical lines going across the whole screen to the left.
In this video, I start out doing some basic troubleshooting in an attempt at tracking down the problem.
00:00 - The TV is clicking and not powering up
00:18 - Lots of tobacco inside the TV! :-(
02:30 - The model number and year of manufacture
03:28 - Vertical colored lines going through the screen
06:20 - Checking voltages
10:19 - Ruling out the input video contol board
11:05 - Ruling out bad flat flex cables
13:30 - Symptoms of an address failure?
13:40 - Disconnecting a flat flex going to the Y buffer
14:10 - Checking temperature at Y buffer board ICs & more
15:54 - Logic board LED is constantly blinking
22:14 - Showing some Amiga demo & game footage on this TV
26:07 - I noticed something possibly related to temperature...
When I disconnect the two flat flex cables going to the two address buffer boards, I get a white noisy picture on screen. This is not strange considering the logic board is disconnected from the address buffers, however, I still get those vertical lines going across the screen at exactly the same place as before. The only difference is that the lines are now more blackish than when the logic board is connected to the address buffer boards.
This most probably means that there is nothing wrong with the logic board in terms of signals going out to the address buffer boards.
I am more and more starting to conclude that there is something wrong with the address buffer board that is handling the left part of the screen, seen from the front of the TV. Either that, or maybe even more likely, there is something wrong with the X-address driver IC that is mounted on the plastic ribbon carrier (the flat flex cable) that is going between the X-address board and the plasma panel. There is a COF (Chip On Film) on this ribbon carrier going between the X-address board and the plasma panel display. This COF is the X-address driver IC. It might have failed, or there might be some other kind of fault with the flat flex cable itself. I have yet to investigate this.
This is Part 1. A part 2 is coming as soon as I have any updates on this repair.