60PA5500 dead as Dillinger - no picture, no sound

[Cipher108]

I have an LG 60PA5500-UG with no picture, and no sound (most of the time, I'll explain).

I've removed the back cover, and checked the three fuses in the power supply. I've also visually inspected for blown caps, but don't see any.

In line with other advice here, I've powered the unit down and restarted with only the zsus disconnected, then again with only the ysus disconnected. No change in state fit either.

Before the unit died (I think it's dead) the USB ports failed one by one. I'm down to one working (if I can ever make the tv work again). I'm thinking this is a problem with the input board. When it's plugged in, a single red led lights up on the board marked LD500 C500. Is this an error code?

Same said for powering up. It clicks on right after I apply power, and the red stand by light next to the power button comes on. However, if I press the power button, there is no click, the red standby light blinks twice, and nothing else happens. Repeated pushing of the power button does nothing.

Where do I go next?

[Moreno83]

Re: 60PA5500 dead as Dillinger - no picture, no sound

You need to measure the voltages going to the mainboard. Just looking at your thread i will say the mainboard is getting the standby voltage but does not turn on the tv.

[Cipher108]

Re: 60PA5500 dead as Dillinger - no picture, no sound

Attached pictures of the input board.

Oh, and about the sound: I did get it to give me some static, but no picture, only once. I think it's stuck on an input with nothing coming in. But I can't change the input to test again because I can't see the screen...

[Cipher108]

Re: 60PA5500 dead as Dillinger - no picture, no sound

Thanks Moreno! When you say "the main board" Is that what I'm calling the "input board"?

[CapLeaker]

Re: 60PA5500 dead as Dillinger - no picture, no sound

Thanks Moreno! When you say "the main board" I'd that what I'm calling the "input board"?

Like in your post #3 first picture. That's the main board.

[ReeceyBurger123]

Re: 60PA5500 dead as Dillinger - no picture, no sound

Probably Bga solder under the main Cpu which is mounted under the heatsink on the Mb. Maybe reflow it see if it sorts it ?

[Cipher108]

Re: 60PA5500 dead as Dillinger - no picture, no sound

Update, I now have sound but no picture. I tried measuring the input voltage to the main board, but my DMM is made for electrical work and not electronics. I sparked it once by touching two pins simultaneously.

I'm going to take that as it having power...

[Cipher108]

Re: 60PA5500 dead as Dillinger - no picture, no sound

Thanks Reecey. I read another post that said to remove the main board and "bake it" at 400° for ten minutes to re flow. I did that, but no results.

[ReeceyBurger123]

Re: 60PA5500 dead as Dillinger - no picture, no sound

Hmm ok I misread this, have you ran the sets test patterns ?

[Cipher108]

Re: 60PA5500 dead as Dillinger - no picture, no sound

Hmm ok I misread this, have you ran the sets test patterns ?

Not sure I can with no image.

[dick_barton]

Re: 60PA5500 dead as Dillinger - no picture, no sound

It bypasses the main board.
If you have an image then you most likely have a faulty main board
If you dont then you need to investigate further.

https://www.badcaps.net/forum/showth...a+test+pattern


Have you measured all the voltages to see if any are missing, IE VA, VS, VZB etc

[Cipher108]

Re: 60PA5500 dead as Dillinger - no picture, no sound

There are two rows of pins, and a key coming of the power board (picture attached). The pins are in rows of nine (top and bottom). I disconnected the wiring harness to the main board, and measured the voltages supplied. They are (name, then measurement)

1) "17V" measured 17.3V
2) "GND" measured 0V (of course)
3) "5.1V" measured 5.1V
4) "Error Detect" measured 5.1V
5) "GND" measured 0V
6) "GND" measured 0V
7) "Stby" measured 5.1V
8) "AC Det" measured 0V
9) "Auto gnd" measured 0V

Then the bottom set of pins

1) "17V" measured 17.3V
2) "GND" measured 0V (of course)
3) "5.1V" measured 5.1V
4) "5.2V" measured 4.8V
5) "GND" measured 0V
6) "GND" measured 0V
7) "Stby" measured 5.1V
8) "AC Det" measured 4.8V
9) "Auto gnd" measured 3.8V

Figuring that "Error Detect" might be an error flag, I unplugged the zsus, and checked again - still 5.1V. Then I reconnected zsus, unplugged ysus, and checked again - it dropped to 0V!

Does this mean there's a problem with the ysus?

[Cipher108]

Re: 60PA5500 dead as Dillinger - no picture, no sound

Next, I checked the power coming into ysus (again, picture attached). They measured

"VS" measured 205V
"VA" measured 55V
"M5V" measured 5.1V

[Hamie]

Re: 60PA5500 dead as Dillinger - no picture, no sound

Run test patterns as previously advised.

[Cipher108]

Re: 60PA5500 dead as Dillinger - no picture, no sound

Run test patterns as previously advised.

I read the post on how to do that. Maybe I'm thick. But it looked like it was for Samsung and Panasonic tv's...

[Hamie]

Re: 60PA5500 dead as Dillinger - no picture, no sound

Upload picture of control board

[Cipher108]

Re: 60PA5500 dead as Dillinger - no picture, no sound

Upload picture of control board

Picture attached to post 3

[dick_barton]

Re: 60PA5500 dead as Dillinger - no picture, no sound

Picture 3 is the main board not the control board



https://www.badcaps.net/forum/showth...ght=tom+plasma

[Cipher108]

Re: 60PA5500 dead as Dillinger - no picture, no sound

Thanks guys. I'm trying to keep up with the terminology (and failing). I appreciate your patience.

[dick_barton]

Re: 60PA5500 dead as Dillinger - no picture, no sound

Follow the link in post#18 which tells you how to complete this test.