LG 50PZ550 No Video or Audio

[avasvani]

Hi,

My LG50PZ550 Plasma TV has a black screen (I know screen is on because I tried each of the driver boards individually and was able to see the difference between the on and off parts) but no audio or video appears to the screen. None of the device menus appear either when they should, which leads me to believe that the screen isn't receiving anything. I measured all the points which guides say to measure and saw no issues. I am now at a loss for what to do, any suggestions?

[Ltank]

Re: LG 50PZ550 No Video or Audio

I always check voltages 1st. Does it have 5vdc or 3.2vdc standby?
If no VS voltage try disconnecting the Y then Z or X board and see if it comes back on. Does the set have sound?

[avasvani]

Re: LG 50PZ550 No Video or Audio

I always check voltages 1st. Does it have 5vdc or 3.2vdc standby?
If no VS voltage try disconnecting the Y then Z or X board and see if it comes back on. Does the set have sound?

It has a VS voltage, but what do you mean by 5vdc or 3.2vdc standby? And the x board relies on the y board for power, how do I work around that? The set doesn't have sound.

[tom66]

Re: LG 50PZ550 No Video or Audio

Since you have a lit up screen, I would consider the main AV board as the fault.

Can you post a picture of your control/logic board? It's the small green board, roughly in the centre of the set's chassis.

[avasvani]

Re: LG 50PZ550 No Video or Audio

Is this the board you wanted? Also, if the menu of the TV itself doesn't show up would it still be the audio board?

[tom66]

Re: LG 50PZ550 No Video or Audio

That's the one.

Unplug the power cord from the TV.

Disconnect the cable that's taped down with the white stuff - it goes off to the main board. Remove the tape, then lift the black plastic latch and gently tug on the cable to remove it.

Then, place a wire jumper between the holes marked R51 and R52. It's right next to that taped down cable. This is the test-pattern connector.

Plug the power to the TV back in.

Do you get a sequence of test patterns?
https://www.youtube.com/watch?v=9LcqLM5TRHk

[avasvani]

Re: LG 50PZ550 No Video or Audio

Hi Tom, I did what you said and I did see the test signal, does that indicate this is the board which needs to be replaced? Thanks!

[tom66]

Re: LG 50PZ550 No Video or Audio

You need to replace the MAIN AV board, the one with the HDMI inputs on it.

[avasvani]

Re: LG 50PZ550 No Video or Audio

Thank you so much for your help! Is it possible you could recommend a place for me to purchase this from? Everywhere I look seems to be sold out .

[tom66]

Re: LG 50PZ550 No Video or Audio

In some cases LG will sell directly to customers but it will be around $150 to $200 for the part. Try calling their part support line with the required part number (beginning EAX)