Vertical black bar on Panasonic 42" Plasma

Do an internet search for this document: PX80_PZ80_PZ85_TG.pdf

Larry

My non-professional guess would be that the C1 board is bad.

I base this on the following Panasonic Technical Guide diagram. It appears you have a vertical block that is bad, not just a vertical line, which would indicate case #2, the C1 board. This seemed to be verified when you disconnected another cable and got the same 3" width line. If it was a different width, it might indicate the Plasma Display Panel (PDP) was defective. Note that your model has the D-board incorporated into the A-board.

Wow, sorry to have mislead you. I was hoping for an inexpensive fix.

The only other components that might cause that block are the PDP/driver ICs, or the A-board (which incorporates the D-board). I've seen those A-boards go cheap for your model ($20) on eBay.

Any way of hooking up that driver IC cable to the adjacent socket on the C1 board, just to try to rule out the PDP?

If you try anything else, please keep us posted.

hi there, did you ever get any further with this? i have the exact same problem.

well, if it helps anyone, replacing the C1 board did not help me either. still missing 1/8 of the screen. i guess the panel is toast? or should i try the A board?

The 2008 PX80/PZ8xxx series have a 2-year factory warranty on the panel (parts only, not labor) so if the panel's integral/non-removeable circuitry is what has failed then that requires replacing the whole panel. So if any of you guys are still within two years Panasonic has to pay for a new panel, and you only have to pay the labor ($200-$400) to have it installed. Several have gone this route after being alerted to it. Some have even had their credit card company pay the labor per their one year extended warranty program

It appears there are 3 possibilities for these symptoms: the A-board, C-board, or the plasma panel.

In this thread, it appears replacing the C and D (or A) boards did not solve the problem, and was assumed the panel was bad.

In this thread, the A board was replaced and did not solve the problem. Then, the C board was replaced and it solved the problem. Thing to note here is that the poster had used a vendor where he could return the board for a refund if it didn't solve the problem.

And then, this OP's thread, where the C board was replaced but didn't solve the problem. The A board replacment was not tried.

So, you replaced the C board, and it didn't solve your problem. Basically, the only other possibilities is the A board, or the panel. It might be worth trying to replace the A board, by using a vendor that will accept returns if it doesn't solve your problem.

Sorry I cannot give a more definite answer, as resolution to this problem seems to be like a crapshoot.

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.

i also have a 42" PZ700, once a couple years ago it developed a vertical black line 1 1/4 wide starting 6 inches from the left side of the screen, going from the bottom up to about the center line, i called Panasonic tech support, even though i was outside of warranty she was willing to help me, she ended up getting me to unplug the tv from my surge protector and plug it directly into the wall, it fixed it!!!
i am sad to say the exact problem has returned, from what the last poster says it was the C3 board? they are on popular auction sites for 3 or 4 bucks. does anybody have a digital copy of the service manual that i could use? or does anybody think i have a different problem?

The service manual for the TH-42PZ700U can be found here, and technical guides here and here. The C-board would be the least expensive start in determining what is wrong, if the manuals do not help.

I have a TH-42PZ700U. I'm seeing the exact same problem described by PhoebeAnn60 and Hedgehog99 -- only my problem is on the lower right side of the screen, and it is not intermittent.

Were either of you ever able to resolve this issue? What was the solution? Thx!

Also, tomwil, the links you provided lead to what appears to be a bogus site. It promises a downloadable pdf of the service manual, but only provides a bunch of deceptively labeled links to other sites -- no actual pdf.

If the assumptions I made in my post #12 above are correct, you need to replace the #4 buffer board, p/n TXNC41HATJ. It's available online for $12-$21. Just google that p/n and pick a site you like. The service manual is also available from several sites; as a last resort you can pay a $5 daily membership fee and get it from at least one pay site. Google "th-42pz700u service manual" and take your pick.

In my case, it was the #3 board, which I purchased for $20 or so. I've been waiting for the problem to be permanent before I go to the trouble of replacing the board (you're lucky!), but am 99.44% confident that it's the problem. These buffer boards are buried pretty deep in the chassis, and the connectors are tricky, so it's not a job to be undertaken lightly, but anyone with a modicum of electronics experience should be able to do it.

Those links work perfectly fine for me. I rely on this site, as well as many others.

Be sure to have javascript active, and no ad blockers. Otherwise, your PC may have a virus, which does redirections.

Huge thanks to both of you for responding so quickly!

PhoebeAnn60, I appreciate your encouragement but "lucky" is not the word I would use. :-) Though I consider myself to be a wizard when it comes to wiring up computers and hi-fi systems, fully dismantling my TV seems rather daunting.

tomwil, I took your advice and was able to download the service manual from that site, though on the pages for the tech manuals instead of the "Get Manual" link shown in your screenshot, I only see a message which says "This file is downloadable free of charge from the site... processing." But the service manual seems likely to be the most relevant of the three -- so thank you!

This image from page 30 of the TH-42PZ700U service manual seems to suggest that my thin vertical line problem is not one of the buffer boards but actually the panel itself -- or maybe I'm reading this image incorrectly? What do you think?

You're lucky in that the fault is not intermittent -- it's much easier to address than one which comes and goes.

I think you're reading the image incorrectly. The caption says. "Fig-1 is the possible defect P.C.B. [printed circuit board] for each local area." As I read the diagram, for the lower left quadrant of the screen, there are a total of 5 boards that are involved: the SC, SS, and D boards (but they affect the entire screen); the SD board (but that affects the entire lower half); and the C3 board (which affects only the lower left quadrant). So, my money is on the C3 board (for this example and MY problem), and the C4 board (for your problem).

Of course, it COULD be anything but the SU board (including the panel), but for $20, it's worth a shot to replace the C4. If it's the panel, it's probably time for a new set.

Well, I've ordered my C4 and I'm gonna try to swap it out myself. I'll let you guys know how it goes. Thanks again for the feedback!

Good for you. I'll be anxiously awaiting your experiences. I'd lay out a white sheet on a large table (to catch any small parts that go astray), then put the set face-down on the sheet and go by the book. Take it slow, group the screws and parts carefully as they're removed, and take notes as you proceed. I think the ribbon cable connectors are the only really tricky bits, so take some time to understand how they work before getting out the big pliers. Don't force anything...

Victory!

The new (used) C4 board from shopjimmy.com arrived yesterday, and today I dove in on the repair project. Took all day, but in the end I turned it on and hollered with joy -- problem solved!

Thanks again to both of you for your wisdom and support!

Thanks to YOU for telling us that it works! I'll get around to doing mine one day now, but for now it's intermittent enough that I can live with it. And "took all day" doesn't surprise me a bit. Well done!

Bumping this older thread in the hopes that someone here can help me out.

My Panasonic TH-50PZ750U recently developed a black line in the lower right-hand section. I've replaced the C6 board but that failed to fix the problem. Is there anything else I should consider replacing before I give up and buy a new TV? D board? SD board?

Thanks in advance.

I'm really surprised that the C6 board didn't fix it, if the problem in fact is isolated to the lower right 1/6th of the screen. Since you're now a pro at replacing these boards, I suggest working your way up the chain: C6->SD->D, etc. , although the likelihood that they're at fault falls off, imho. If it's not an intermittent problem, a good shop might be able to repair it cost-effectively, but with the price of these things these days, it might be tempting to trash it and go for a 60" this time .

FWIW, remember that I had decided to wait for my problem to stop being intermittent? It did -- it went away altogether.

well i downloaded the service manual, bought a C3 board, changed it out and the problem persists. i found the ribbon cable on the C3 board that corresponds with my black stripe, unplugged it got white garbage instead of a black stripe. what to try next?

The fact that unplugging the C3 board affects the problem suggests that you're getting warm, at least. If we assume the C3 board does in fact control what you see in that particular area, but replacing the board didn't help, either both boards are bad (unlikely), or something else is amiss - perhaps a bad cable or connection upstream, etc. I assume you can't swap ribbon cables for 2 panel segments -- I think someone else said there's no slop in the cables allowing this -- which is what I'd really like to try now. It seems to me, though, that the panel is probably OK, since it can display white (albeit garbage) and black, but I may be wrong. I tried to trace the block diagrams back to the main diagram, but quickly got lost in PDF-land; probably easier with a hard-copy manual. May be time to try a good shop, especially if the problem is not intermittent. Sorry I couldn't be of help.

would the D board be next? looks like the boards get expensive from here on in, maybe i should just part this one out and buy a new one. it will not be a Panasonic. my Panasonic 50" has a very narrow green line from top to bottom. i bought this brand because i was told they were the cadillacs of plasmas, the most reliable, guess i got suckered in.

Can you post a picture or complete description of your problem? In post #13 you said it was "a vertical black line 1 1/4 wide starting 6 inches from the left side of the screen, going from the bottom up to about the center line" but now you say it's "a very narrow green line from top to bottom". Those 2 different symptoms imply 2 different boards, I think.

2 different tv's, black stripe is on my PZ700 42", the green stripe is on a 50" PX80? i think