Lg 50pc3due plasma-- no video, audio ok

[mbdmtrasdl]

Greetings All,
I currently work on jukeboxes, pinball machines, and computers, but this is my first attempt at a non-crt television.
I currently have this Lg 50pc3due, 2006 Plasma, with audio and no video. vs, va both ok. Very little service information, but I believe it is a close relative of the 50PC1DR. I pulled up the LG Training manual for the 60py2dr (and 50pc1dr), page 52, and printed out the chart of expected voltages. All voltages, including those on the SMPS, Control board Voltage regulators, show ok and the osc is working. The only place they are wrong is the P1 header of the Z-Sus board...No voltage is correct, i have 0 v where there should be some and voltage where there should be 0...I am pretty sure of the header numbering as the black wire is noted as pin 12. I have not dragged the scope out to check those waveforms yet, the scope has never been my best friend.
Being a stranger in this land of Plasma, looking for a guide to point me in the correct direction for a solution.
thanks for helping
mike

[ReeceyBurger123]

Re: Lg 50pc3due plasma-- no video, audio ok

Probably failed Ipm module under heatsink on Zsus, have you checked the Zsus fuses ?

[mbdmtrasdl]

Re: Lg 50pc3due plasma-- no video, audio ok

I checked again, but I don't see any fuses on the Z-Sus board...All other fuses in the set check good.

[mbdmtrasdl]

Re: Lg 50pc3due plasma-- no video, audio ok

is there a simple way to pretest this board prior to board swap? perhaps using a vtvm or vom?

thanks for the help
mike



























'pretest" the

[ReeceyBurger123]

Re: Lg 50pc3due plasma-- no video, audio ok

The fuse for the Zsus is actually on the Ymain check both fuses on the Ymain.

[mbdmtrasdl]

Re: Lg 50pc3due plasma-- no video, audio ok

checked fuses, all ok. replaced z-sus board and now screen flashes white for a 1/8 sec both when set is turned off or on, but no picture/raster on screen...sound OK. Any help appreciated.
mike

[mbdmtrasdl]

Re: Lg 50pc3due plasma-- no video, audio ok

Replaced Zsus board as above, still no picture. I now notice that the led , on the control board (that shows the oscillator working) turns on for a second or 2 during start-up,then goes dark. Then it shows for a second or two during shut-down sequence. Time to replace the control board??
thanks
Mike