Panasonic TH-42PZ85U (2) 1"1/4 inch vertical line down middle of screen

[ahwen]

Thanks in advance for reading this. This issue first started 2-3 months ago where the two lines would only appear occasionally and slowly getting worst, and is now displaying permanently. These two lines are color changing at times, flashing various colors, and sometimes in solid black which blocks the picture completely. These two lines seems to be "worst" when TV are first start up and a little "better" when warms up.

I am hoping to narrow down to a board or cable that I can replace. This set is a 42 inch so there is only two buffer IC board, but the two line location seems to located across the two IC board, therefore I am wondering if the D board or something more higher level is the issue?

[tom66]

Re: Panasonic TH-42PZ85U (2) 1"1/4 inch vertical line down middle of screen

This is most likely a loose connector on the C board, this model is prone to it. You will need to take the back cover off and show us pictures. It is nt a buffer board problem, as the buffer board controls the rows, not the columns, of the image.

[ahwen]

Re: Panasonic TH-42PZ85U (2) 1"1/4 inch vertical line down middle of screen

Attach is a troubleshooting guide for panasonic plasma I found online, seems to be a good guide.

[tom66]

Re: Panasonic TH-42PZ85U (2) 1"1/4 inch vertical line down middle of screen

See my signature above for service manuals. I have a lot for Panasonic plasmas.

[ahwen]

Re: Panasonic TH-42PZ85U (2) 1"1/4 inch vertical line down middle of screen

Hi Tom, thanks for the quick reply! There is a good picture of the inside of my set in the attached PDF, page 5. Where is the location of the C board you are referring to? and what connection I should focus on? thanks.

[tom66]

Re: Panasonic TH-42PZ85U (2) 1"1/4 inch vertical line down middle of screen

I really need a picture of your chassis because there are at least two different versions of this TV with a slightly different plasma panel inside.

[ahwen]

Re: Panasonic TH-42PZ85U (2) 1"1/4 inch vertical line down middle of screen

Okay, the first pic below is the overview, the second is the focus on A board and below, the last pic is the CB8 ribbon off the C2? buffer IC board. When i pushed in the ribbon cable on CB8, i see reaction from the two color line onscreen immediately. Is this indicative of the issue? What are my next steps? I haven't try hard to remove the ribbon cable because it is locked in....

[tom66]

Re: Panasonic TH-42PZ85U (2) 1"1/4 inch vertical line down middle of screen

Yes, this is your problem, the connector is loose. Very common.

https://www.badcaps.net/forum/attach...7&d=1369700521

Please do not push on it while the panel is energised, as you run the serious risk of damaging the driver chip, which would make this very nice TV a very heavy paperweight. All modification to the connection MUST be done when the set is unplugged with a delay of at least 30 seconds from the set being off. In addition do not run the panel with the screws loose, as they connect to a heatsink which cools the driver IC. Each IC has 384 channels operating at around 75V (each channel can switch between 0V and 75V) and they control the picture that appears on the screen. The density is very high, very tiny transistors on chip <10mm^2, they are not forgiving at all if they receive an anomalous condition, and since it is bonded to the plasma panel, it is not user replaceable.

Simply unscrew it, unhinge the latch, lift the ribbon up, place it back down, hinge down the latch and screw it back down. Don't touch any exposed metal on the connector at any time and try to touch the frame of the TV often to reduce ESD hazard.

[ahwen]

Re: Panasonic TH-42PZ85U (2) 1"1/4 inch vertical line down middle of screen

Many thanks for walking me through this. I have reseated the ribbon cable and the issue remains after putting everything back together. Two vertical bars, now one solid black (happens b4 but could change back to a transparent color later), the other vertical bar continue to change color.

Would this means either the cable or the panel is bad which probably not worth replacing, or there is a chance the C2 board's CB8 "port" is bad which may worth replacing?

[tom66]

Re: Panasonic TH-42PZ85U (2) 1"1/4 inch vertical line down middle of screen

It's probably not a bad panel. I'd try cleaning the connector out first with some contact cleaner. Allow 30 minutes drying time after applying cleaner. C board replacement may be necessary. Panel failure would leave permanent bars, not temporary ones. In fact the only major issues these sets appear to have is a rash of loose connectors. I have fixed a 46" TH-46PZ80B which had a loose connector (in a different place) and lots of other people have similar issues.

[waitery]

Re: Panasonic TH-42PZ85U (2) 1"1/4 inch vertical line down middle of screen

Hi Ahwen, I had this same set with the same issue, except it was a solid bar, right down the middle of the screen. I put a new "D" board in and the issue went away. Cost my $50.00 for the new board, but it worked like a charm. Again, same set and same issue, bar just looked a little different and was one solid bar. To your point, it would show up after the set started to warm up. I hope this helps you out!! Let us know if it does and good luck!

[ahwen]

Re: Panasonic TH-42PZ85U (2) 1"1/4 inch vertical line down middle of screen

Appreciate all for the inputs. I will try in this sequence: clean ribbon contact; replace C2 board; and finally replace D if necessary. I will post back with the final resolution. Thanks!

[ahwen]

Re: Panasonic TH-42PZ85U (2) 1"1/4 inch vertical line down middle of screen

UPDATE:
Replaced both C board and the buffer board but issue persist.

One of the vertical bar is almost permanently displaying green. At this point, perhaps the ribbon cable is the issue and based from what I read, the ribbon cable is fused to the panel so there is no repair.

thanks

[tom66]

Re: Panasonic TH-42PZ85U (2) 1"1/4 inch vertical line down middle of screen

There is the possibility it is a D board issue.

[ahwen]

Re: Panasonic TH-42PZ85U (2) 1"1/4 inch vertical line down middle of screen

My bad, I meant I have replaced the D board and the buffer board. I didn't replace the C board. Any way to confirm the ribbon cable might be the issue here?

[tom66]

Re: Panasonic TH-42PZ85U (2) 1"1/4 inch vertical line down middle of screen

If flexing/reseating the cable (with power off) changes the patterns, consider the cable a potential fault.

[ahwen]

Re: Panasonic TH-42PZ85U (2) 1"1/4 inch vertical line down middle of screen

That appears to be the case, when messing with the ribbon cable the line color would change. Also took a picture of the ribbon cable, at left is the suspected bad ribbon; at right is a normal functioning ribbon.

On the bad ribbon cable the "long skinny rectangle" area in the middle the top area seems to be burnt and on the good ribbon cable, the color seems to be more consistent. Would this be the cause? Is it repairable?

[tom66]

Re: Panasonic TH-42PZ85U (2) 1"1/4 inch vertical line down middle of screen

The long skinny rectangle is the driver chip. If it has truly overheated it cannot be replaced.

[ahwen]

Re: Panasonic TH-42PZ85U (2) 1"1/4 inch vertical line down middle of screen

Thanks for the confirmation and the comments. I think I will stop here and cut the loss.

Anyone need parts from a TH-42PZ85U?

[husseinkapasi]

Re: Panasonic TH-42PZ85U (2) 1"1/4 inch vertical line down middle of screen

I figured out it was because of the loose connection on small white ribbon cable between the C1 (C10) and C2 (C20) boards. The ribbon cable was loose where it connected on the C1 board (C10). So I re seated it and the Vertical lines went away . Initially I tried to re seat the brown/Tan ribbon cable with a metal heat sink and driver IC which connected to the connector CB4 on the C1 board. The other end of this brown/tan ribbon was going inside the Plasma screen and was located on the bottom of the plasma screen. Then I realise that since I had removed all the ribbon cables going to the different board while I was trouble shooting for the 13 Red blink hence I must have not re-seated them properly. So after I re-seated the tiny (hardly 1 inch long) cable connecting the C10 (C1) board to the C20 (C2) board the problem of pink vertical lines was resolved. So now I have a fully working Panasonic Plasma Th-42PV8H TV 