LG 50PS2000 plasma tv with double image

[Erikswe]

As the title says. The picture has a double image vertically
I was wondering where to start the fault check.

[R_J]

Re: LG 50PS2000 plasma tv with double image

I would start by checking just the panel using auto_gen test patterns.
Unplug tv, dissconnect the cable between the main and control borad, locate and short the two points on the control board labeled AUTO_GEN and plug it the tv a see if the fault is still there while viewing the test patterns

[Andrew F. Ali]

Re: LG 50PS2000 plasma tv with double image

i would start by checking just the panel using auto_gen test patterns.
Unplug tv, dissconnect the cable between the main and control borad, locate and short the two points on the control board labeled auto_gen and plug it the tv a see if the fault is still there while viewing the test patterns

+100

[R_J]

Re: LG 50PS2000 plasma tv with double image

If the control board has a P6 plug (lower left on board) short pins 1~2 for Auto Gen. The fault could be a poor connection with the lvds cable also, (wide flat cable between control board and main) try re-seating this cable a few times if the autogen tests are ok.

[Erikswe]

Re: LG 50PS2000 plasma tv with double image

Some additional information. The tv has not been used for a lo g time so when I turned it on the picture was perfect for a few minutes but then the double image returned and when on for a lo her time the screen continues getting worse with the double image flickering.and even a few thin horizontal coloured lines and on the top right corner some small shadows of red, but once in a while the screen becomes perfect for a few seconds.

That's the auto gen plug. Just to be clear, is 1 and 2 to the left?

[R_J]

Re: LG 50PS2000 plasma tv with double image

Pin #1 is marked with a white triangle. If the tv has'nt been used for a while I would re-seat all the connectors and maybe even clean and re-seat the flat cables between the panel and buffer boards.

[Erikswe]

Re: LG 50PS2000 plasma tv with double image

I tested the auto gen patterns. The pictures has less distortions but in some tests the double image is flickering but much less

[R_J]

Re: LG 50PS2000 plasma tv with double image

That test eliminates the main board and I can't see the power supply causing the issue. Try reaseating the y-sus to buffer board plugs. try tapping on the boards and see if the fault changes.

[Erikswe]

Re: LG 50PS2000 plasma tv with double image

I clean all flat cables on the left side with alcohol and repeated them. At first I got 2 black horizontal lines, thin, and repeated them again and the lines disappeared. I cleaned and repeated the flat cables from the logic board and now it's almost perfect. Just a liiiitle small flickering left

[Erikswe]

Re: LG 50PS2000 plasma tv with double image

Update. After letting the tv stay on the flickering got back more and there is a sound...hard to explain..but humming sound coming from the board to the left. When I touch one on the flat cables from the logic board the sound disappeared and the screen looks a bit better. Maybe reset the cables again and clean them

[R_J]

Re: LG 50PS2000 plasma tv with double image

The Y-sus board will make some noise, and pressing it might effect it, Remove the board and check for poor solder connections, I see from SJ images that the bottom of the Y-sus board likely has pads stuck to the bottom to reduce this noise.
Also check the ground contact points where the screws hold the board to the chassis, if there is any signs of black corrossion, clean both the board and the metal chassis, Then INSTALL ALL SCREWS before retesting.