LG 60PZ750-UG no picture, no sound, has glow

[rockrunner86]

I have a LG 60PZ750-UG that has no picture or sound, however it does show some light output in a dim room. I have done some basic checks based on reading from other posts on this forum.

Power supply readings

VS - 204v
VA - 55v
M5V - 5.16v

Y-SUS

VY -180v
VSC - 149v

Z-SUS

VZB - 110v

I have disconnected the ribbon cable leading from the board containing the HDMI inputs from the board with P51 and P52 to initiate self-test. Upon doing so the TV lights up and scrolls through a series of colors and patterns.

This is where I am at currently. My initial thought is the board containing the HDMI inputs (which i believe is the main board) is faulty. Before trying to find a replacement of this board I would like to have a greater certainty this is the problem.

The TV is currently hanging on a wall mount as it was the best location I could test with power, video/audio signal, and leave the TV without risking damage to the glass face. I could not photo the power supply board from this location, if needed I will pull the TV and get this photo.

Thank you in advance for the help.

[sordids999]

Re: LG 60PZ750-UG no picture, no sound, has glow

I have disconnected the ribbon cable leading from the board containing the HDMI inputs from the board with P51 and P52 to initiate self-test. Upon doing so the TV lights up and scrolls through a series of colors and patterns.

so i would say you have a faulty main board

[tvtimmy]

Re: LG 60PZ750-UG no picture, no sound, has glow

+1
had this problem on 2 lg plasmas. New mainboard fixed them both.

[rockrunner86]

Re: LG 60PZ750-UG no picture, no sound, has glow

Thank you both!!! I ordered a main board and will report back with the results.

I also have a dead Panasonic Plasma I might tackle next.

[rockrunner86]

Re: LG 60PZ750-UG no picture, no sound, has glow

Replaced main board, problem still exists.

Suggestions?

[dick_barton]

Re: LG 60PZ750-UG no picture, no sound, has glow

That's unusual in that most threads that I've read indicate that if you can obtain the colour test pattern then it equates to a faulty mainboard.
It may be worth your while just double checking all the connectors have been reconnected and are seated accurately.

[rockrunner86]

Re: LG 60PZ750-UG no picture, no sound, has glow

That's unusual in that most threads that I've read indicate that if you can obtain the colour test pattern then it equates to a faulty mainboard.
It may be worth your while just double checking all the connectors have been reconnected and are seated accurately.

I've double/triple checked all connections.

Faulty replacement main board?

[dick_barton]

Re: LG 60PZ750-UG no picture, no sound, has glow

That's always a possibility but would be interesting to see what others may think.

[rockrunner86]

Re: LG 60PZ750-UG no picture, no sound, has glow

Any other suggestions?

[vinceroger69]

Re: LG 60PZ750-UG no picture, no sound, has glow

I would say mainboard too can you send your replacement back and get a refund/another board

[Alastair E]

Re: LG 60PZ750-UG no picture, no sound, has glow

Ive had the Y-SUS cause weird issues--including no picture.
--The cause are the buffer-chips--on the y-- that pass the serial picture info to the buffer-boards, one fails you may get only half a pic or a different one goes, you only get every other line working--or no pic at all.

[dick_barton]

Re: LG 60PZ750-UG no picture, no sound, has glow

Hello Alastair,
He does say in post #1 that he successfully ran the test pattern so wouldn't that exclude any buffer faults, or not?

[freakaftr8]

Re: LG 60PZ750-UG no picture, no sound, has glow

Could be faulty ribbon cable going from main board to logic or could be bad logic

[mmartell]

Re: LG 60PZ750-UG no picture, no sound, has glow

I will say it again because it's solid advice especially for LG main boards... heat it up with a hair dryer focusing on the main processor. Then fire it up.

[ReeceyBurger123]

Re: LG 60PZ750-UG no picture, no sound, has glow

I will say it again because it's solid advice especially for LG main boards... heat it up with a hair dryer focusing on the main processor. Then fire it up.

+1 or mainboard not correct for that panel.

[freakaftr8]

Re: LG 60PZ750-UG no picture, no sound, has glow

Yeah there is that possibility that your replacement main board could still have the same problem a little heat on the processor and around the surrounding components not going to hurt anything. Try turning the TV off heating up the processor and surrounding components including eeprom NV RAM and then powering backup. Sometimes I have found on LG main boards that no amount of heat will cause it to show a picture while the TV's been on but a quick power down and power up will bring it right back

[rockrunner86]

Re: LG 60PZ750-UG no picture, no sound, has glow

Thank you for the info. Im going to try the hair dryer

[rockrunner86]

Re: LG 60PZ750-UG no picture, no sound, has glow

Okay, TV has the replacement board in it hit it with some heat from the hair dryer on the mainboard, turned the tv on and everything was looking good back to normal then went blank again. How much heat should I apply seems promising! Is the hair dryer fixing some bad solder joints?

Thanks!!

[tvtimmy]

Re: LG 60PZ750-UG no picture, no sound, has glow

Send it back and get another. I know they are getting harder to find, but why pay for a crappy one? If no returns, try a reflow, out of the set. I am using a Wagner paint stripper set on LOW only(so I dont blow a bunch of parts off the board). Let us know how it turns out.

[mmartell]

Re: LG 60PZ750-UG no picture, no sound, has glow

The hair dryer is a diagnostic tool only and will in no way repair that fault.