I am a long time electronic tech and recently starting repairing lcd and plasmas..
I have a lg50px10 that everything functions, picture comes on, colors, osd contrast etc changes as adj's are made but picture is extremely faded. It is all there but very weak. I have tried replacing the ysustain...no changes. I also verified the voltages from the lvps and they all are consistent with the service manual and labels on the tube.. 129 vdc, 60vdc, 5vdc
The customer said he hear a loud pop (cap i guess) and the picture suddenly faded. I just want be sure that this couldn't be the screen itself before I try an x sustain board. What else would cause this typically?
There is a logic board that has two led's one is in a green state and the other is red.
The board and signal associated with the red indicated led is.
LED D109, IC 100, Signal Name: NSTD pin 53, page 23 of service manual
Drawing label: PY.Built.in.PDP Analog, SW & 3D Comb, drawing 1 of 3
Can the plasma tube go bad and cause this type of problem?
Hi: Your problem is the X- sustain board, the PDP Chip for this board has failed, usually when a loud pop is heard its one or the other of the boards Y or X in this case the X.
Hi:
The red led is just indication that the unit has standby voltage to the signal board, It should not be any concern at this point, it just lets you know the unit has 5 Volts to the microprocessor system control. The answer to your second question is yes it is the large Chip under the heatsinks that go bad on these boards and are not user replaceable, replacing the board is the only option.
Ok. Good luck!
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Hi kyshu
I am a working tech myself and the problem you described has x/z sustain written all over it.
If there was no picture i`d say go for the ysus first and check the VA and VS.
But apparently you checked those.
So from experiences that i have every day i would go for the x/zsus.
Let me know how it goes.
Hi again
Somehow i didn`t get a notification about your reply.
Will check some info and be back with you shortly.
Hi again
Was looking for x and ysus kits for your model.
Hard to say since the same part maybe in use in different boards.
The i.c thats located under that large heathsink can sometimes be subbed with stk`s
Like if the number on it is YPPD-J014A then you can sub it with STK795-811A
That part is available here;
http://www.richtechparts.com/search.html...
Those parts are hard to come by even when you know what you`re looking for,
According to LG there`s no kit for them, Guess they`d rather sell whole boards.
let me know how it goes
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Ok. Just a few more questions before I close this out. Do you have any idea as to the red led indication. Is this normal or associated with the x problem? Of course I should have known it was the x board since I ordered the y board.. Murphys Law...
Also, there are several people that do repairs on the x and y sustain. Is there any source for component parts? for these LG engines? How are they finding sources for parts? One more. Is the module that you mentioned located under the large heat syncs?
Thanks for your help.
I should have the x sustain board in tommorow. I am waiting to accept your response in case i need further help... Thank you and I am sure you are correct, but holding off just in case..
Thank you the x-sustain board fixed the problem.
Paul Schuster, louisville, ky
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