Lg 3d plasma 60pz550 i've got sound but no picture

[strohs99]

Re: Lg 3d plasma 60pz550 i've got sound but no picture

These contact points with these labels were all could find. didn't recognize a specific resistor for either.

I tested those contact points and the voltage for both were jumping 13v down to 1.4v

[strohs99]

Re: Lg 3d plasma 60pz550 i've got sound but no picture

I also found the VZB points on the Zsus. is that the resistor under the markings?

[tom66]

Re: Lg 3d plasma 60pz550 i've got sound but no picture

Ah OK so this set does not use resistors, that is fine.

Since the voltages are jumping, please try pulling the Y-buffer boards out from the Y-sustain. You will need to unscrew them then pull them back slightly. The orange ribbons hooking them to the panel can stay.

Then see if the voltages stabilise.

[strohs99]

Re: Lg 3d plasma 60pz550 i've got sound but no picture

No change in voltage fluctuation with the upper and lower buffers detached from the Y sus.
While i was back there i tested the VZB contacts on the Z sus its steady at around 108v

[tom66]

Re: Lg 3d plasma 60pz550 i've got sound but no picture

OK this indicates the fault is probably on the Y-sustain board, just to check, you did disconnect the white connectors not the orange connectors?

[strohs99]

Re: Lg 3d plasma 60pz550 i've got sound but no picture

Yes the hard white connectors. the buffers are dangling from the orange ones

[tom66]

Re: Lg 3d plasma 60pz550 i've got sound but no picture

Good, you can try testing for shorted transistors on the Y-sustain or just replace the entire board.

Might be a good idea to test for buffer board shorts too - still a little worried that you may have chipped/cracked the panel right on the edge - this can kill the panel and the buffer, which can also damage the Y-sustain in some cases.

See here: https://www.youtube.com/watch?v=51SZ...Y&noredirect=1

[strohs99]

Re: Lg 3d plasma 60pz550 i've got sound but no picture

tom66. I really appreciate the help to this point. So I'll test the buffers for shorts.(that video instruction made it simple to understand testing), order those if needed and order a new Y sus board just in case (still worth the cost,if it fixes it or not)

Then I'll repost a conclusion after I've accomplished this.

THANX AGAIN

[tom66]

Re: Lg 3d plasma 60pz550 i've got sound but no picture

What I am saying is if your buffer tests bad look really carefully for a crack. It can be right on the edge and you might not see it until you look with a bright light. It has caught out others before.

[strohs99]

Re: Lg 3d plasma 60pz550 i've got sound but no picture

The lower buffer tests bad/short. has continuity. Upper seems fine. Should I order an Y sus board also or wait?

Also can I look around the casing with a strong flashlight (without removing the casing), too see if the screen is cracked along the edge?

[strohs99]

Re: Lg 3d plasma 60pz550 i've got sound but no picture

Do you think the lower buffer's short was the cause of the lines at the bottom of the screen before the screen went dark and can that buffer cause the Ysus to be damaged?

[tom66]

Re: Lg 3d plasma 60pz550 i've got sound but no picture

The lower buffer short could well have caused temporarily the bottom of the panel to go blank - this would have eventually have killed the buffer so it looks like you have tracked down the cause. Coincidence.