LG 50PX950 Clicks, Turns off instantly

[hehehh]

Re: LG 50PX950 Clicks, Turns off instantly

I am not really sure - i was using an amp and had the TV sound turned off. Since the screen is blank I can not be sure that I can select the input and turn on the volume. Is there another way to test for sound?

[capkid]

Re: LG 50PX950 Clicks, Turns off instantly

You may be able to blindly switch inputs with the remote until you arrive at an input with sound.

[hehehh]

Re: LG 50PX950 Clicks, Turns off instantly

I will try that tonight when i get home. It seems though the test will only be conclusive if i hear sound - if i don't it may be that there is no sound or that i can not blindly select the right input.
What is the theory behind this test - are we trying to figure out whether the electronics are fine but the display is bad?

thanks!

[tom66]

Re: LG 50PX950 Clicks, Turns off instantly

The goal is to test one part of the electronics vs another part of the electronics, when the display panel on a plasma fails it typically produces no light like you observe and emits a loud buzzing sound. They usually only fail due to being cracked/hit.

Locate the control board, it's the board below the power supply. Can you get a picture of it?

[hehehh]

Re: LG 50PX950 Clicks, Turns off instantly

I will take some pics tonight.
And on the display, it actually does get a little lighter when i turn the TV on - you can definitely see a difference b/n on and off state. IT is just that there is no picture/OSD/Etc.

thanks,

[tom66]

Re: LG 50PX950 Clicks, Turns off instantly

Can you get a picture of the control board?

[capkid]

Re: LG 50PX950 Clicks, Turns off instantly

We're trying to eliminate the suspects. Preliminary testing indicates that your Y-Sus, Z-Sus, and power supply are working correctly. The typical remaining suspects are the panel, control board, and main board, which is what Tom is having you walk through next.

[hehehh]

No Sound; pics attached

I played with the remote/inputs but could not get sound out of the TV. I only used an HDMI cable that i know works; i could not find an old AV cable to try as well.

Also attached are pictures - one overall and on of the 2 boards below the PSU. Where to next?

Thanks for the help in diagnosing this!

[tom66]

Re: LG 50PX950 Clicks, Turns off instantly

OK, I've highlighted two points.

Turn the set off (power unplugged.)

For the two small holes, take a small piece of wire and jumper them together.

Disconnect the cable at the position highlighted. All other connections are to be left as-is. To disconnect it, lift up the small latch and carefully remove the cable.

Then, plug the set in.

After a short delay, do a series of test pattern screens show up?

[hehehh]

Re: LG 50PX950 Clicks, Turns off instantly

Will do - i won't have time tonight but hopefully tomorrow afternoon i will do it and report back. Thanks tom66!

[hehehh]

Re: LG 50PX950 Clicks, Turns off instantly

Finally got to the TV - the test patterns showed up. First the whole screen lit up in diff colors, then white strip moving sideways and upside down...
So the display works?

thanks,

[tom66]

Re: LG 50PX950 Clicks, Turns off instantly

Yep, it looked a bit like this? (patterns may vary)
If so, the main board is the fault.
http://www.youtube.com/watch?v=xgrvRc2a

[hehehh]

Re: LG 50PX950 Clicks, Turns off instantly

tom66, the link for the video is broken, can you re-post please?
the main board is the one in the pic you sent, correct? is this repairable or do i need to get a new board?

thanks,

[tom66]

Re: LG 50PX950 Clicks, Turns off instantly

whoops.
http://www.youtube.com/watch?v=xgrvRc2JVVQ

The main board is the one with the video inputs on it.
It is NOT the one you just did the jumper on.

In general main boards are rarely repairable; you can do some things such as check voltage regulators... https://www.badcaps.net/forum/showthread.php?t=22231 and check any visible fuses. Usually it is a processor problem, due to corrupted firmware or eeprom... but you can't fix those without the firmware working unfortunately.

[hehehh]

Re: LG 50PX950 Clicks, Turns off instantly

yes, the tests looked like that - i had the sequence starting at the 4th second of the video.
Is the main board easily source-able?

[tom66]

Re: LG 50PX950 Clicks, Turns off instantly

Oh. I totally missed that you have a mystery board between your control board and main board. Does this TV have 100 / 120 Hz function? For motion enhancement? I have never seen that board in a plasma before. Unfortunately because of the 2 board setup it is difficult to determine which of those boards is bad.

I think it is motion converter for 120Hz or 3D converter.

Can you tell me the EBR#######.... number printed on the main board and this board which goes between the main board and control board.

[hehehh]

Re: LG 50PX950 Clicks, Turns off instantly

I did not see an EBR notation, but i believe the main board is EBR61125901 and if that is correct the small board is EBR61125201.

[hehehh]

Re: LG 50PX950 Clicks, Turns off instantly

pics of the boards

[capkid]

Re: LG 50PX950 Clicks, Turns off instantly

Hmm, I've never heard of the PC board: http://www.shopjimmy.com/catalogsear...=Circuit+Board

Yes, it looks like the main board is indeed EBR61125901.

[hehehh]

Re: LG 50PX950 Clicks, Turns off instantly

yep, i looked up shopjimmy and both boards are out of stock. Is there another place that would carry them?

thanks,