Zenith Z50PG10 - Voltage Discrepancy 60V vs 5V ?!

[Alastair E]

Re: Zenith Z50PG10 - Voltage Discrepancy 60V vs 5V ?!

Has anyone ever seen a YSUS with ONLY the top being defective? I have tried several Upper Buffers and the same result. (With the upper removed I have bottom but, no top

When Upper Buffer is installed there is no backlight nor video

Any ideas?

Plasmas Dont have 'Backlights'! Backlights are ONLY used on LCD Crap!

Plasma screens use a completely Different Technology. Its Photo-Emissive not Photo Transmissive like LCD rubbish.

Plasma have a Priming Glow derived by Y-SUS working with X/Z-SUS, visible in Darkened room.

IF you've confirmed the buffers you've been using are good--Then highly likely the panel itself is short,--maybe cracked-- somewhere in the upper half.

[electronicsurplus]

Absolutely NO shorts checked each thououghly

Absolutely NO shorts Tested Thoroughly

That is the confusing part.

I have seen a YSUS either bad or not. Never only 1/2

I wonder if I am missing something?

All buffers received free from shorts on check?

I was wondering whether there could be a bad output or something only affecting the upper buffer?

How to test a panel for short(s) ?

I have tested both buffers and neither is shorted at all

As far as testing using diode mode from ground to output pins using a zipper like fashion

Is there another way to test these buffers ? EBR50039001

Here is a pic

[tom66]

Re: Zenith Z50PG10 - Voltage Discrepancy 60V vs 5V ?!

Both upper and lower receive the same sustain output from the Y-sustain. It's not possible for a Y-sustain to drive only the top buffer badly. You could have a pinched ribbon cable.

[electronicsurplus]

Re: Zenith Z50PG10 - Voltage Discrepancy 60V vs 5V ?!

So, there is only 1 output from the YSUS to both buffers Correct?

Then I will check for a pinched ribbon or possible panel short. I think I will try to isolate the short by removing the IC Driver Chips one by one until the top turns on somewhat

Thank you all for the input