LG 42PC5DC plasma tv clicking on off

[jose6326]

Re: LG 42PC5DC plasma tv clicking on off

tom i did what the instructions said
i clipped the negative and positive leads to the resistor where it shows "-Vy"
and i adjusted the pot closest to the resistor which you say is not the right one

but after looking around on the board i found another pot behind the frame/bracket
So im guessing its that one

[tom66]

Re: LG 42PC5DC plasma tv clicking on off

That one is for SET DN or SET UP. -Vy and Vsc on these are on the stand-up boards, I thought, though it is a slightly newer panel so I could be wrong on that.

[tom66]

Re: LG 42PC5DC plasma tv clicking on off

I just checked, that pot under your bracket is for -Vy and there is no Vsc adjustment on these panels so you will have to adjust -Vy for minimum maldischarge (usually make it around 10V or so more negative.) Increase Vzb by a few volts as well. Then try SET UP and SET DN.

[jose6326]

Re: LG 42PC5DC plasma tv clicking on off

thanks tom

the service manual says to do it in white wash mode
is it bad to do these adjustments when i have a picture on the screen?


what about the pot that says RAMP?
what is that for?

[tom66]

Re: LG 42PC5DC plasma tv clicking on off

Access white wash mode from the user adjustment menu, ISM Method I believe.

RAMP can be adjusted later, for now dont' touch it.

[jose6326]

Re: LG 42PC5DC plasma tv clicking on off

i had it in white wash mode
i was wondering what would happen if it was in normal mode

[jose6326]

Re: LG 42PC5DC plasma tv clicking on off

I just checked, that pot under your bracket is for -Vy and there is no Vsc adjustment on these panels so you will have to adjust -Vy for minimum maldischarge (usually make it around 10V or so more negative.) Increase Vzb by a few volts as well. Then try SET UP and SET DN.

Tom the label calls out -145 for -Vy
So I should go down to-135?

I set it at -135 and the picture does not look any better it kind of looks worse than before

I set it back to -145 and the picture looks better
If I go more negative will I damage anything

[jose6326]

Re: LG 42PC5DC plasma tv clicking on off

I misread your post tom
I guess I was supposed to go down to -155

[tom66]

Re: LG 42PC5DC plasma tv clicking on off

You cannot damage anything if you do not go beyond around -170V on these.
Yes set it to -155V for now and if that's no better try -160V or -165V.

[jose6326]

Re: LG 42PC5DC plasma tv clicking on off

sounds good

thanks tom

[jose6326]

Re: LG 42PC5DC plasma tv clicking on off

I tried -155, -160, and-165 and the picture got worse
You can actually see more green fuzz while the picture showed

So I turned it back to -145
This is the best I can get it

Is there anything else I can adjust?

Im thinking the panel is going bad since its an old model

Also is the z board suppose to make a small high pitch noise when I change channels and when the immages change?
Im thinking there might be an issue there as well but im guessing

[tom66]

Re: LG 42PC5DC plasma tv clicking on off

I would try dropping Vzb.
If those fail you can try SET UP and SET DN. Turn SET UP back a bit and SET DN forward a bit.
(back/forward is arbitrary, but they should move in opposite directions.)

[jose6326]

Re: LG 42PC5DC plasma tv clicking on off

tom do you mean z bias for "Vzb"?

also i was scrolling thru the service manual you provided

starting on page 67 this looks more like the boards i have instead of page 49 as you suggested

page 67 is for panel 42X4A
my panel is 42X4

page 49 is for panel 42X2 and 42X2A

is there a difference?
you are the pro so you know more then i do

[tom66]

Re: LG 42PC5DC plasma tv clicking on off

Yeah PDP42X1 is 2005, 42X2 is 2006, 42X3 is 2007, 42X4 is 2008 I think. Different model year, different parts...

[jose6326]

Re: LG 42PC5DC plasma tv clicking on off

so then i was correct?

i just looked at the label and it is a 2008 model
so i should be following page 67 not 48

[tom66]

Re: LG 42PC5DC plasma tv clicking on off

I thought there were only minor differences between 42X4 and 42X4A, I may have been wrong. I don't touch old LG plasma panels due to IPM problems.

[jose6326]

Re: LG 42PC5DC plasma tv clicking on off

Ok I am doing the adjustments again
On page 75 it show my exact z sus board compared to page 55 which doesnt have the same component setup

Anyways it says test ground and drain on Q2 and adjust pot
Is the drain the center leg?

[jose6326]

Re: LG 42PC5DC plasma tv clicking on off

Ok I figured it out

I turned the pot all the way down and now the red and green snow is gone when I change the channels

Now the only problem is that you can see more of the red snow at the top of the screen at all times when there is a picture

I guess I have to get the tcon flashed

[capkid]

Re: LG 42PC5DC plasma tv clicking on off

Drain is the tab or the center pin; they're connected.

Edit: I always use the tab to test to avoid shorting out the mosfet.

[jose6326]

Re: LG 42PC5DC plasma tv clicking on off

Im guess thats all I can adjust for now till I get the board flashed