I have a Panasonic TH-42PZ700U with an intermittent problem wherein a vertical black line appears in the lower left quadrant of the display. It appears only on startup, is about 1 1/4" wide, about 10" in from the left side of the display, and rises from the bottom to the horizontal centerline. this has happened 4 times in the last 4 or 5 months, always appears in the same place (as near as I can guess), and goes away after a short period of time.
A couple of days ago I discovered that I have an extended warranty from American Express which expires today. However, having filed the claim, it's good forever, but I need an estimate for repair from an authorized Panasonic service center. I called the local PSC, but they say they can't provide an estimate without seeing the problem, which makes some sense. Their solution is to keep the set in the shop until they see the problem. Since it only happens on startup, I don't see how they'll ever see the problem any time soon, and even if they do, I don't see why they'll have any more information than they've got now.
They claim that just my description of the problem doesn't give them enough information to diagnose the problem, but for a lot of money they'll come out and look at it. I have seen a bunch of information on the Web, however, that claims that this problem is almost certainly traceable to either one specific board (no p/n given) or the display. I'm willing to replace the suspect board to at least rule that out, but they say they can't narrow it down to one board. Frankly, I trust the Web community more than them at this point, but will stand corrected if I hear a good argument from somebody who knows what he's talking about.
Any help would be appreciated. I see that I'm getting an Old Thread Warning, but I'll try here anyway, and maybe start another thread later if need be, but this thread's title seems to fit pretty well.
Update: I eventually found a Panasonic "Technical Guide and Troubleshooting Handbook" that suggests (p. 53) the "C4" board is at fault if the problem occurs in the lower left 1/6th of the display. These "buffer boards" (p/n TXNC41HATJ) are $20, so it's worth a try. It could, of course, be the panel, but I don't want to go there right now. Unfortunately, I had erroneously assumed the panel would be divided into quadrants, so I've got to wait until the next occurrence to confirm the problem is in the lower left, not the lower middle.
Further update: Failed to notice that the illustration on p. 53 had some problems. Buffer boards were illustrated for the larger sets only (6 boards) and mislabeled at that. There are only 4 boards on the 42" set (I was right -- it is divided into quadrants), and assuming the numbering scheme holds (#1 for upper-right, moving CCW around the screen, as viewed from the front), I'm pretty sure I really need the C3 board, TXNC31HATJ, also under $20.
Last update: Finally found the real service manual, and confirmed it's the C3 board, which is on its way, on my doorstep for under $20. Panasonic and 3 Authorized Service Centers were of absolutely no help.
Sorry for this long-winded post; hope it may help someone else someday.