LG 50PC3D - Picture slow to react and weird colors

[Bullgawd]

Heres the story - bought the TV with a bad power board. Order a replacement board on Ebay and install it. Check the outgoing voltages and adjust to specs according to label on inside of set but notice green and red speckles and just a generally dim and weird colored picture. What would cause everything to look strange like this? Im trying to understand what the Ysus and Zsus boards do and how to test them but I am extremely new to TV repair. I also managed to find a service manual by searching a thread on here but none of the examples they show in the PDF look similar to my problem. It also seems like it takes a second for the picture to "fill in" so to speak.

[tom66]

Re: LG 50PC3D - Picture slow to react and weird colors

You have a bad Z-sustain. The fault is caused because the Z-sustain is not pre-charging the panel properly, meaning it cannot change rapidly. Also, the colours often appear with a deep purple tinge, even on white scenes. There are often fuses on the Z-sustain that blow which can cause this; test them. Also check the logic and power connectors as they can sometimes come loosened when you work on the TV.

[Bullgawd]

Re: LG 50PC3D - Picture slow to react and weird colors

Yeah it almost looks blue in person and greens look awful. The dashboard screen on my Xbox 360 is ridiculous. I will check and see if there are fuses on the Z-sus and report back. Thanks for the prompt reply!

[tom66]

Re: LG 50PC3D - Picture slow to react and weird colors

Yeah it almost looks blue in person and greens look awful. The dashboard screen on my Xbox 360 is ridiculous. I will check and see if there are fuses on the Z-sus and report back. Thanks for the prompt reply!

I believe the blue is caused because the panel (because of the faulty Z-sus) is not properly converting the UV light into visible light, so you are seeing the blue/deep violet end of the spectrum, but that's only speculation on my part.

[Bullgawd]

Re: LG 50PC3D - Picture slow to react and weird colors

Checked the Z-sus board, no replaceable fuses.

[tom66]

Re: LG 50PC3D - Picture slow to react and weird colors

Checked the Z-sus board, no replaceable fuses.

Post a picture of it. Some basic tests can be done.

[Bullgawd]

Re: LG 50PC3D - Picture slow to react and weird colors

Dont have a pic of mine but here is the board that is in the tv

[Bullgawd]

Re: LG 50PC3D - Picture slow to react and weird colors

LG Electronics 50PC3DUD
LG Electronics 50PM1M
LG Electronics 50PX5D
LG Electronics 50PY2DR
LG Electronics Z50PX2D
LG Electronics Z50PG10
LG Electronics 50PC1DR
LG Electronics 50PX1DH
LG Electronics 50PC3D
LG Electronics 50PC1DRA
LG Electronics 50PX2DC
LG Electronics 50PX1D
LG Electronics 50PC3DH
LG Electronics 50PY2DRUA
LG Electronics 50PC1DRUA
LG Electronics 50PC3DHUD
LG Electronics 50PX1DUC
LG Electronics 50PX2DUD
LG Electronics 50PX5DUB
LG Electronics 50PC1DRAUA
LG Electronics 50PX1DHUC
LG Electronics 50PX2DCUD
LG Electronics 50PM1MUC
LG Electronics 50PC3DUE
LG Electronics 50PX4DRUA
Vizio P50HDTV20A
Vizio PH50HDTV10A
Vizio VP50HDTV10A
Vizio P50HDM


All the models it can fit. Apparently there are more from what Im reading (Zenith, HP, Sony, Maxent, Polaroid etc). 6871QZH044A or 6870QZC004A is the part number.

[Rlljr103082]

Re: LG 50PC3D - Picture slow to react and weird colors

I have a lg plasma TV 50pc3d, issue: discolored, dark display. Picture's
https://www.dropbox.com/sh/jkyilhxtj...sC99hz3fa?dl=0

[Rlljr103082]

Re: LG 50PC3D - Picture slow to react and weird colors

Forgot to mention the lower heat sinks on both board are cool top heat sinks are warm.

[Alastair E]

Re: LG 50PC3D - Picture slow to react and weird colors

It'll be the IPM on that cold heatsink of the z-sus. I Think the ERC IPM is the bottom one if I recall, and a fairly common failure on a set at around 15-20 thousand hours use.

They can fail Open circuit (as in your case probably) as well as short, but the short usually ends up making the set dead or blowing the board fuse....

[Rlljr103082]

Re: LG 50PC3D - Picture slow to react and weird colors

I have replaced all 3 boards z,y,aND power supply, TV will not power on blinking green light turns red. Any suggestions?

[PowerAmpFreak]

Re: LG 50PC3D - Picture slow to react and weird colors

You have to take a few steps back and replace one board at a time.

[Rlljr103082]

Re: LG 50PC3D - Picture slow to react and weird colors

I Replaced z one week, y next week, power supply board this week. Ready to scrap it and sell the parts I just bought. I replaced the z board 2 years ago Worked fine till last October.

[jeffegg2]

Re: LG 50PC3D - Picture slow to react and weird colors

are these ebay boards? I won't buy ebay boards anymore, got caught on mine and it was a waste of time.

[Rlljr103082]

Re: LG 50PC3D - Picture slow to react and weird colors

Got mine on ebay, how do I test the boards?

[tom66]

Re: LG 50PC3D - Picture slow to react and weird colors

On the IPMs (devices under the large heatsinks) check for shorts between VS, SUS_OUT, and GND on one IPM, and ER_HI/ER_LO to ER_IO. Each will read something on diode mode one way, but there should be no bidirectional reading (below 1kohm or so)