Re: Lg 42PC1R

Yes mine seems to be ok now. Still need to check the voltages though.
What's your Vs doing when the Vy is fluctuating?

Re: Lg 42PC1R

YSUS board is a 6871QYH053B on the sticker and 6870QYH005B 42V8&X3 on the board. When I pulled the bottom W9NK70 (for set down) and powered it up you got the -200v, this is same result as pulling the ribbon to the CTRL Board. I think the Vy is fed to the setup and setdown FETs first, then on to the 3 FETS above which work in parallel.

Re: Lg 42" plasma model p2pc3d-ud

Cheers, I found the fault with the YSUS and have removed the EEPROM and loaded the 88D4 firmware with success. Just need to check the voltage levels now.

Re: Lg 42PC1R

Found one of the 59N25 FETs was sc, which was pulling the -200v down when the CTRL board was plugged in. Obviously with it unplugged there was no control over the setup setdown FETs, which meant the -200 didn't get through to the 3 in parallel.
Set is now on the updated firmware, just got to check the levels.
Is there a way to make the set produce it's own full white test?

Re: Lg 42PC1R

Put a scope on the output from the little Vy inverter PCB and it looks like it is trying to start up but trips out on over current as the voltage starts to rise

Some weeks ago I was given the above plasma so I could learn a little about how they work and look to repairing it. Initially it didn't switch on, which was an easy repair to the power supply. When I got that working the picture was dark so I replaced the ZSUS IPM which gave a much better picture but with some red speckled mal discharge on dark screens. I then tried swapping the YSUS IPM to see if that improved things which it didn't. I also changed the 5 FETs with no improvement. I was going to give up at this point, so I put the set back together and ran it for a day on test. All was fine apart...

Re: Lg 42" plasma model p2pc3d-ud

I removed the EEPROM today and tried the file for the 42x3a, which did nothing. Not even displaying the temperature LEDs on the CTRL board. I then removed the EEPROM again and programmed the original file the tv came with. This powered up similarly to the 42X3_3DCS4 file, so I guess in learning my smt soldering technique I killed something early on.
I have noticed that I don't have a -Vy voltage with the CTRL board ribbon plugged in to the YSUS? With it unplugged I see -200v?
I did initially repair this set by replacing the PSU...

Re: Lg 42" plasma model p2pc3d-ud

Thanks for the link.

I removed the EEPROM from the board and tried to reprogram it but my programmer wouldn't erase or write to it. In the end I bought a new one 29L320T from RS and programmed that. All verified ok.

Now it's installed back on the board the panel has no picture. With the auto test pins shorted you hear the familiar switching noise from the drive boards. The CTRL board has the temp LEDs lit.

The panel is a PDP 42PC1D, and the CTRL board is a 42V8&X3 6870QCH0C6C version, it says...

Re: Lg 42" plasma model p2pc3d-ud

Hi, can anyone point me in the right direction to find the updated EEPROM file for a 42V8&X3 board, or are any of you guys offering an update service? Thanks