samsung 58 inch plasma

[adamp91gvm]

Re: samsung 58 inch plasma

also with the 3-4 jumper on or off ?

[tom66]

Re: samsung 58 inch plasma

BETWEEN pins, black on black highlighted, red on red highlighted on the buffer board connector.
3-4 jumper, take it off for now.

[adamp91gvm]

Re: samsung 58 inch plasma

-61v I get if like this ?

[tom66]

Re: samsung 58 inch plasma

Yes, that's what I meant. Now, try with buffer connectors removed.

[adamp91gvm]

Re: samsung 58 inch plasma

-22.2v

[tom66]

Re: samsung 58 inch plasma

That reading is unexpected, and very odd. Not sure what to make of it.

Please check the voltage across those red capacitors I highlighted previously.

[adamp91gvm]

Re: samsung 58 inch plasma

Just seen this on the back of a buffer

[adamp91gvm]

Re: samsung 58 inch plasma

-110v of the red cap

[tom66]

Re: samsung 58 inch plasma

That's OK...
I think part of your Y-Main is defective, can you see any point for testing voltages at -Vscan/-Vsc or Vsch? I cannot see them on photos.

[adamp91gvm]

Re: samsung 58 inch plasma

yer at the top of the board vsch

[tom66]

Re: samsung 58 inch plasma

What do you measure on that point? Black probe on ground this time.

[adamp91gvm]

Re: samsung 58 inch plasma

vsch -31.2v vsacn -189.4v

[tom66]

Re: samsung 58 inch plasma

Hmm, both VSCAN and VSCH are OK. I could not see those on pictures before, makes it much easier!

With those voltages you SHOULD have screen glow, even if it's really faint.

This leads to only a few possibilities:
- bad panel (cracked glass on outer edge or middle; check carefully)
- bad buffer board
- partially functional control board (unlikely)

You would need an oscilloscope to see if the Y-main waveforms are all correct. But so far, it appears Y-main is working.

[adamp91gvm]

Re: samsung 58 inch plasma

thats the first thing i checked was the glass its perfect how would i test buffers

[tom66]

Re: samsung 58 inch plasma

You unfortunately need a scope to test the buffers. Also, the glass could be cracked under the frame, so you might want to try lifting that off to double check.

You could also try checking the voltage across the red caps on the X-main board to see if that's functioning properly, just in case.

[adamp91gvm]

Re: samsung 58 inch plasma

100.3v across the x main caps

[tom66]

Re: samsung 58 inch plasma

Hmm, the X- and Y-main voltages should match very closely, but a small offset could be acceptable. There's not much else to suggest other than to replace boards one at a time, if you can't get hold of a scope to check the waveforms.

[adamp91gvm]

Re: samsung 58 inch plasma

ill ask in work tomorrow see what the engineers have or the design fella's ill keep u posted thanks for your help so far hope i can do this one i have plans for it

[tom66]

Re: samsung 58 inch plasma

You work in an engineering firm? They probably have a scope you can borrow for the night (my boss has frequently allowed me to borrow meters when away from my lab) - and you could use that on the Samsung LED TV too, and check if main board sending right signals to panel.

Get a 10X probe too, if you can, and prefer a digital scope over analog, though both can be used.

[adamp91gvm]

Re: samsung 58 inch plasma

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