LG 60PC1D-UE picture messed up

[tom66]

Re: LG 60PC1D-UE picture messed up

I don't know what the fault is for sure, but I'd be surprised if Y and Z are the cause.

[shelby5041]

Re: LG 60PC1D-UE picture messed up

well logic boards are cheap...i hope u r right

but the inermittent issues to me would serm like bad solder joint or part that is starting to fail such as ipm

i would think a logic board would be either bad or good....not intermittent

no?

[shelby5041]

Re: LG 60PC1D-UE picture messed up

and its getting worse.....now i cant get a perfect pic intermittrntly like i did a week or so ago......

[tom66]

Re: LG 60PC1D-UE picture messed up

Logic boards can fail intermittently, and give a variety of symptoms... I would be considering it.
It's worth also checking the Vscan, -Vy and Vzbias against the sticker ratings.
See if they change during the fault or fail to match sticker ratings.
You can find a service guide for this panel (not the TV), I think it is 60X6, in my signature.
Search for "50R1" under LG...it's in the same guide.

[shelby5041]

Re: LG 60PC1D-UE picture messed up

update....just replaced ysus...tv seems to have good picture now....5min test only

will test longer.later today ...im hoping its now fixed...we will c

tom...it doesnt appear logic board was the issue....but cant say for sure until further testing

[shelby5041]

Re: LG 60PC1D-UE picture messed up

hey tom...did further testing today and with replacement y board installed tv is doing exact same thing as before... same type of issue...exact same

so that should tell me the y board is not the problem?...and you said it doesnt appear to be z board issue....

should i replace the logic like you think it is?...or could it indeed b a z board issue?

thats why i asked you about this tv...you know a lot about plasma tvs

[shelby5041]

Re: LG 60PC1D-UE picture messed up

when i replaced the y board today the pic was great for first 5 min so i guess i was ....prematurely hioping it was fixed

wrong...wrong wrong....

as said above the tv is behaving same as when i had other y in it so i have to assume the y is not the problem...

[tom66]

Re: LG 60PC1D-UE picture messed up

I said before I don't think it's a Y or Z issue because this isn't a typical Y/Z failure.
I think you should check -Vy/Vscan/Vzbias as mentioned before to rule out other issues.

[shelby5041]

Re: LG 60PC1D-UE picture messed up

what would checking those voltages say about the issue and board at fault?....and what board do i check them on?.....y and z?...i now believe the y is good

the logic board is only $30......if u think i should replace it

im getting a refund on the y i bought

[tom66]

Re: LG 60PC1D-UE picture messed up

Look at the documentation I provided you on my website. See post #44. It goes through the testing procedure.

[shelby5041]

Re: LG 60PC1D-UE picture messed up

ok thank u..i will

[shelby5041]

Re: LG 60PC1D-UE picture messed up

Ok I downloaded Serb man

It's a very nice manual....wish all were like that...

Will do some reading and testing later

Thank you tom

U r awesome

[shelby5041]

Re: LG 60PC1D-UE picture messed up

Hi tom here are voltages using test points per serving manual....

Panel specs

Va 60v
Vs 193v
Vsc 110v
Vy -65v
vsetup 250v

Actual readings

Va 61.3
Vs. 194.8
Vy 64.6
Vsc fluctuating and out of range above 600v
Vsetup no reading/out of range above 600v

[shelby5041]

Re: LG 60PC1D-UE picture messed up

Also

Zbias 170v actual.....specs 170v

Ydrive waveform ....2v.actual...waveform did not resemble specs at all.....specs 220v

[shelby5041]

Re: LG 60PC1D-UE picture messed up

if vsc and vsetup voltages are messed up doesnt that mean y or y buffer issue?

[tom66]

Re: LG 60PC1D-UE picture messed up

Make sure you're using the right ground as specified in the manual, Vsc and Vsetup are not always tested wrt to chassis ground.

[shelby5041]

Re: LG 60PC1D-UE picture messed up

vsc and vsetup tested per serv man using test points across resistors


what di the bad readings at vsc and vsetup mean?

[shelby5041]

Re: LG 60PC1D-UE picture messed up

should i try to test vsc and vsetup with other boards disconnected to try to isolate?

[tom66]

Re: LG 60PC1D-UE picture messed up

Could be a Y-sustain issue or a control board issue...hard to tell.
If you have a scope or access to one that may be useful.
You can try with the buffers disconnected.

[shelby5041]

Re: LG 60PC1D-UE picture messed up

tom
when i disconnect buffers from y....bad vsc vsetup

if i disconnect logic board from y.with buffers connected to y.....i get good vsc and vsetup



vsc 110.6v
vsetup 249v

what can this mean?