LG 50PC1D need help guys

[PowerAmpFreak]

Hi all.
Got an LG plasma 50PC1D. Came in with this failure:
Picture flashes up bright for 1/10 of a second or so. Goes black for one or two seconds, then start's over , flashes up bright in an endless loop.

I found a blown upper buffer board (6871QDH088A) replaced but still no difference in behaviour.

According to my mains power meter , set draws about 200W constant from the mains.
When the set flashes white , a sharp sound could be heard , probably from the high power consumption during the "flash".

Pulled out the Y-SUS , without finding anything "obvious" like shorted IPM's or power mosfets.

Is it safe to operate the set without the lower buffer / just the new upper in case the lower has been damaged?
I have measured across the lower buffer without finding anything strange.

Y-SUS part#: 6871QYH039B

[freakaftr8]

Re: LG 50PC1D need help guys

this does not mean you do not have a open IPM. You can run the set with one buffer and but you can also run it with no buffers. But I would advise having at least one buffer installed feel each IPM for a cold one after a few minutes of operation. What you're describing sounds like a bad lower ER IPM on YSUS. when the set is on and you see the bright flashing on the screen still here at significant ticking sound coming from one of the IPM modules?

[tom66]

Re: LG 50PC1D need help guys

Bad ER-IPM breaking down internally or something similar. Seen it before.

[PowerAmpFreak]

Re: LG 50PC1D need help guys

The ER-IPM generates ticking...
Did not dare to push it so long to make the heatsinks hot (or not).
OK, so replacing the ER-IPM (the upper of the two) will probably make it good then?

[mmartell]

Re: LG 50PC1D need help guys

I have the exact fault here with a rebranded 50PC1D (Toshiba) and I am about to order an ER IPM as well. This will be my last messing with these IPM's, especially where they are paired up. Just replaced one in a 60PC1D and blew after probably less than 10 hours of use.

I read here it is important to replace with the exact module and suffix.

[PowerAmpFreak]

Re: LG 50PC1D need help guys

Yeah, it's not the funniest of the jobs I can imagine.
I hate IPM's and favor the discrete designs, but that's another story!

[nismo]

Re: LG 50PC1D need help guys

Hi

Sorry to jump your thread, but I was wondering if you could help me in providing the details of the components (value/markings) located on the power board.

The components are shown on the board as C802 and D801 which are located between the two heat sinks.

I have attached a photo to show actual location.

Any assistance would be appreciated.

Thanks

[Cornboats]

Re: LG 50PC1D need help guys

C802 is a capacitor
D 801 is a diode