Plasma LG 42PC3RA led blinking

[daroo]

I have this 42 inch plasma, the problem is that I have no image.

Opened the back and I found a bad 3300uf cap and replaced it, I have also replaced the other 3 that were near the bad one.

The tv still doesn't work, I ear the relay clicking but there is no picture. the green led blinks.

The fuse near the 220v imput is ok, and also the fuses in the other boards.

I have checked the voltages: Va: 58v and Vs: 0.2v (but only between the first and second click of the relay)
it should be : Va:60v and Vs:185v

Is there something I can check to find the problem?

[daroo]

Re: Plasma LG 42PC3RA led blinking

i've disconnected the y-sus and the green led stays on. Checked all the voltages and they are ok. So I think it's the IC on the y-sus because i found that is a common problem.
The chip is 4921QP1037A.
I'll try to change it.
Is it the correct way to solve the problem?

[daroo]

Re: Plasma LG 42PC3RA led blinking

If I disconnect the ysus the tv turns on with no picture but sound.

I removed the ic under the heatsink on the ysus because it looked shorted with my multimeter and I have read it's common that this hybrid ic goes bad.

I will order the sanyo equivalent and try the swap. Is there something I can check to see if there is anything else shorted?

Wish me good luck, this swap will be a tricky job for me

[daroo]

Re: Plasma LG 42PC3RA led blinking

The right chip was STK795-821, I ordered it from china for 22$.

Soldered in place and the tv is working fine, no red sparkles. no need to adjust voltages.

Very very good, thanks to this fantastic forum!

[steph06000]

Re: Plasma LG 42PC3RA led blinking

hello
i search to repair my lg
and i have same symptom
one question to you
when you say disconnected y-sus
you say all connections or just supply ??
thank for your answer and sorry for my english
bye

[ReeceyBurger123]

Re: Plasma LG 42PC3RA led blinking

Steph take pictures of the back of your tv please.

[steph06000]

Re: Plasma LG 42PC3RA led blinking


hello
not mine but the same
bye

[ReeceyBurger123]

Re: Plasma LG 42PC3RA led blinking

Ok the Ysus is the large board on the right of the set and the Xsus is the board on the left, they have big power cables going to and from them unplug them at one end and see if the tv at least powers on.

[steph06000]

Re: Plasma LG 42PC3RA led blinking

hello
i have have unplug all card but same led blinking

[ReeceyBurger123]

Re: Plasma LG 42PC3RA led blinking

Ok so you have a Dmm ?

[steph06000]

Re: Plasma LG 42PC3RA led blinking

when you write Dmm it is digital multimeter ?? yes y have

[ReeceyBurger123]

Re: Plasma LG 42PC3RA led blinking

Yes, ok right do you get the Vs and Va voltage on the psu with Ysus and Xsus disconnected ?

[steph06000]

Re: Plasma LG 42PC3RA led blinking

184 for vs 60 for va
with or without cards plugged
i have replace c49 on y-sus but same problem
i have clicking sound on y-sus
no shorted vs/gnd on board fuse ok

[ReeceyBurger123]

Re: Plasma LG 42PC3RA led blinking

Ok checked fuses on Zmain and Ymain ?

[steph06000]

Re: Plasma LG 42PC3RA led blinking

fuses ok on all cards

[mmartell]

Re: Plasma LG 42PC3RA led blinking

Is the sound a ticking and is it coming from the large heatsink ? The ipms can also fail "open" causing them to tick instead of shorting and blowing the fuse.

If so it would need to be replaced.

[mmartell]

Re: Plasma LG 42PC3RA led blinking

By the way Reecey you got your left and right mixed up

[steph06000]

Re: Plasma LG 42PC3RA led blinking

ok
I go to buy STK795-821
cross the finger !!
thanck for your help
when Soldered i come back here for news
bye

[ReeceyBurger123]

Re: Plasma LG 42PC3RA led blinking

Ok let us know Steph

[mmartell]

Re: Plasma LG 42PC3RA led blinking

Posted in the wrong thread...