Just as bktemp clearly pointed out in reply #4, and as other posters have also pointed out after that, those electrolytic capacitors on the power supply board have definitely gone bad and need to be replaced. I think that it's very likely that these caps are what's causing the problem, since insufficient smoothing of the supply voltages for the main board might affect the operation of that board. At least one of the supply voltages for the main board probably has a lot of ripple on it, which should be easy to see on a scope.
It becomes even more obvious when looking at the symptom at 18:49 in the video. A problem with either the Y sustain, Y buffer, Z sustain or X address board can cause a number of problems, but the symptoms usually then look completely different than what we saw here. Vertical or horizontal stationary or flickering lines or bars, horizontal lines flickering across the whole screen, dead portions of the image etc etc... The symptoms from those boards failing can be many, but what I saw in this video looked more like something being introduced already in the main board, which of course is due to the bad output caps for the main board in the power supply.
Looking at the statistics over common faults on plasma TVs (and CRT TVs too for that matter), the power supply output capacitors for the different power rails are the no 1 common issue when these devices fail. This is not strange considering these capacitors are operating in a very warm environment. The capacitors in this particular TV (as in many other plasma TVs) are sitting in the middle of two fat heat sinks as can easily be seen in the picture from reply #4, and warm ambient temperature does not go hand in hand with long operating life when it comes to e-caps, as we all know.
I really cannot understand how Dave could miss these bad capacitors. I noticed them pretty much instantly when the power supply shot started at around 5:52 into the video, and I was just waiting for him to spot them and mention something about them. Starting from 12:17, we are getting a close up of those caps and Dave is even waving around with his spudger over them, yet still misses to see them...?
Like someone else mentioned, I'm almost wondering if Dave did it on purpose just to check to see that we are awake and paying attention when watching his videos.
Also, I would like to mention something else about this particular episode.
I think Dave is awesome, and I have been giving Dave a thumbs up on every video he has released since about two years back now. But this is the first video that I felt that it didn't really deserve a thumbs up. (I never dislike videos, because that is extremely disrespectful towards the uploader - In this case, I just didn't click on thumbs up for the first time in more than two years.) The reason being that I felt that Dave's attitude towards the plasma TV in this episode was a bit disrespectful towards the hardware itself, so to speak. The attitude of "No one wants it, no one uses them anymore and they are nowadays nothing more than obsolete worthless piece of junk" does not comply with my own moral standards and values, and if that is what Dave really thinks, I can then not help but asking myself:
1. When Dave saw the plasma TV in the dumpster, why did he go through all the trouble of bringing the 50 kg beast into the lab? He obviously doesn't want it because he has no space for it and it consumes too much power, and he doesn't show much interest in repairing it either. So why did he take it then? It doesn't make any sense.
2. How does Dave know that "no one uses plasma TVs anymore"? Has he asked around to see what kind of TV technology different people all over the world are using these days? I for one prefer plasma TVs over any other kind of flat screen technology for a number of reasons, and I'm sure I'm not alone in this.
3. How come Dave doesn't mind salvaging parts from the TV and throwing the rest of it to the trash which will then eventually end up in the landfill (why not take mother nature into consideration for a change?), but he's unwilling to repair the TV even though replacing a few capacitors in the power supply will actually take a lot less time than it takes to salvage most of the boards (or at least some of them) for parts? I can understand that he doesn't want to keep the TV for himself due to the power consumption etc and that is fine, but why not fix it by replacing a few caps and then put it on eBay with a starting bid of a buck or so? Then it will end up in the hands of someone who actually appreciates it and can find some use for it. At the same time, Dave has earned a few bucks from selling the TV in a working condition. So in other words, it's a win-win situation. Now isn't that a lot better than having most of it going to the landfill?
I have noticed this disrespectful kind of attitude towards obsolete hardware in some of Dave's previous videos as well. I can also say for sure that I am definitely not the only one who has noticed this, because I have seen other people point this out in the YouTube comments for other videos, and it's easy to see that people are in agreement considering the number of thumbs up these kind of comments have gotten.
One of the better episodes I've seen lately is episode #722. It looks like Dave is in his best mood in that episode, and he delivers a cheerful presentation and has a very humble attitude towards both his viewers and the hardware that was inside his mail. But I must say that I was a bit disappointed when seeing this plasma TV episode because of Dave's seemingly unwillingness to even lift a finger to try to repair the TV, but instead planning on killing it completely by taking a few parts out and sending the rest right off to the landfill, just like that.
Come on, Dave. You could at least try to replace the caps and (if needed) do some basic troubleshooting like checking the voltages for ripple etc before binning the whole TV.
I think that the message Norcal715 delivers at the end of almost all of his videos is a very nice one: "With your help, we can keep these things out of the recycle bin and out of the landfill."
Dave if you'd like to have fun with giving this panel a fitting funeral as it's already dead....
Interesting post. However, the TV is not dead. Look at 18:49 in the video. There you can clearly see that the TV powers up and is even showing something on screen. That is not what most people would refer to as being "dead".
If you are referring to the plasma display panel itself... well, there is no evidence of the plasma panel in that TV being dead. On the contrary, it looks like there is nothing wrong with it at all.
The flickering shown at 18:49 could of course be caused by the camera as well, just as when filming CRT screens. But Dave did mention that the TV screen is flickering so this is not very likely to be a 'camera vs TV refresh rate'-kind of issue.
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