LG 42PC1DA distorted pinkish when turned on

[zango123]

Re: LG 42PC1DA distorted pinkish when turned on

A little paranoid as I do not want to get shocked...

So I am touching the metal circled in white?

[tom66]

Re: LG 42PC1DA distorted pinkish when turned on

Let me clear this up. Probe the marked areas.
Your Vzbias should measure 100V steady -- hold reading for several seconds and see if it is stable.

[zango123]

Re: LG 42PC1DA distorted pinkish when turned on

held contact 20 seconds. multimeter read steady at 99.

[zango123]

Re: LG 42PC1DA distorted pinkish when turned on

but I did not connect to the cable box and wait for the distortion to come up... all I did was power up...

[zango123]

Re: LG 42PC1DA distorted pinkish when turned on

my apologies, I see you had mentioned... screen up with fault visible...
let me test again.

[zango123]

Re: LG 42PC1DA distorted pinkish when turned on

ok retested during the fault. the voltage is not stable.. it stays at 99, then every few seconds jumps randomly 122, 130, 219, then back to 99 for a few seconds, then it repeats.

[tom66]

Re: LG 42PC1DA distorted pinkish when turned on

That is definitely bad though I was expecting it to drop out while the set was running not increase. Can you make sure your meter is away from the display while operating (just in case the interference created is too much.)

[zango123]

Re: LG 42PC1DA distorted pinkish when turned on

So tried it again with the meter away from the tv...
First I got a steady reading for a good 20-30 seconds.. I figured the I had gotten interference before. But, then I took the probes off and back on and was getting the erratic readings once again. It goes up wildly... 155, 220, 300, then back down and steady...

So at this point I'm a little unsure.

By the way, I had my phone in my pocket and now its dead... coincidence?

[tom66]

Re: LG 42PC1DA distorted pinkish when turned on

OK, right now I am thinking the Z-sus should be replaced.
One thing to check: On the Z-sus, there is a power connector which brings the voltages Vs, Va. Can you see it? Can you measure what you see on those pins?

[zango123]

Re: LG 42PC1DA distorted pinkish when turned on

Can you show me how to scope it. Here is a picture with the cable unplugged.

[tom66]

Re: LG 42PC1DA distorted pinkish when turned on

Connect the cable (but NOT when the TV is on - wait a few minutes if it has been recently switched on) then stick your probe in the exposed metal around where the wire goes into the connector crimp. Ground (black lead) in same place as before. Expecting around 185V.

[zango123]

Re: LG 42PC1DA distorted pinkish when turned on

OK, so with the cable attached I will scope the circled points.... look ok?>

[tom66]

Re: LG 42PC1DA distorted pinkish when turned on

Yep. You only need to check one of the VS points, they are the same.

[zango123]

Re: LG 42PC1DA distorted pinkish when turned on

got it thanks... I'll check tonight...

[zango123]

Re: LG 42PC1DA distorted pinkish when turned on

I'm going to ground on the screw nearest the VS, VA connectors... not on the scree I used last time.

[tom66]

Re: LG 42PC1DA distorted pinkish when turned on

That's fine,.

[m33x]

Re: LG 42PC1DA distorted pinkish when turned on

could the RED lava be the light from lamp(s) being red? if so ... bad lamp...

[tom66]

Re: LG 42PC1DA distorted pinkish when turned on

This is a plasma display. It does not use a lamp! The differences between a plasma and LCD are described here, along with the general theory of operation.