Plasma tv zenith (lg ?) 60pv220 works 10 min and shuts down

[anibal2100]

Hello everybody. This is my first post here and I'd like to thank you in advance for any help I can get to solve this problem.
This set is almost identical as the LG 60PV400.
The unit works for about 10 minutes and then shuts down.
If I turn it on it will work for another 10 (or so) min and again will go off.
Once or twice just the picture will go off and the sound will stay on so I discarded the mainboard. When that happened I had a chance to check voltages on the PS:
V 5V = 5.1V (ok)
V 17V = 17V (audio ok)
Vs = 202 V (should be 204V)
Va = 57 V (ok)
Y-main
Vsc = 0V
Z-sus
Vzb = 0v
V18V (from Y-main to Z-sus ) = 4.7V

This last voltage will go normal (18V) once I cycle the TV.

Could be a logic board problem ?

Thanks again for any help !

[Nick's Tvs]

Re: Plasma tv zenith (lg ?) 60pv220 works 10 min and shuts down

Sounds like cracked solder joint either on the power supply or on one of the sustain boards. You should be able to fix this by checking all transistors/diodes screwed into the heat sinks of the power supply along with any components in close proximity to the pads used by those transistors/diodes. Check the transformer as well those can get hot.

[anibal2100]

Re: Plasma tv zenith (lg ?) 60pv220 works 10 min and shuts down

Thanks Nick !. I'll start reviewing all joins first hour tomorrow and will post the results.

[Hamie]

Re: Plasma tv zenith (lg ?) 60pv220 works 10 min and shuts down

If this TV uses the z-sus EBR67820001
Then you need to inspect the solder joints on the coils.
Stop using, or even testing the tv untill you've inspected these - if they completely break free from their pads it will lead to an expensive and difficult repair.

[anibal2100]

Re: Plasma tv zenith (lg ?) 60pv220 works 10 min and shuts down

I already checked all (one by one) solders and they look perfect (under stereoscope). The problem remains the same, I'm thinking the logic board could be the issue
By the way, yes Hamie, it has z-sus EBR67820001 but fortunately solders are all good. You are right I have another TV (LG 60pv400) with the problem you described and is a nightmare, I just resolder the coils, replaced 6 IGBT's and the Y-main (which was working fine) shorted ! I just gave up on it.

Returning to the Zenith, the weird thing is that it works fine for 10 ~ 30 min
and a couple of times just the picture went off with sound ok.
I watched this video and make think about the logic board :
https://www.youtube.com/watch?v=HNzpnnlkiV4

What do you think ?

[Hamie]

Re: Plasma tv zenith (lg ?) 60pv220 works 10 min and shuts down

It's possible but there could be a whole host of problems that cause no picture.

Check voltages when the picture goes blank.

VZB
-Vy
Vsc

See if any drop, if they do then concentrate on that board.

Run test patterns with mainboard disconnected. See if the fault Remains.

[anibal2100]

Re: Plasma tv zenith (lg ?) 60pv220 works 10 min and shuts down

Now it has sound and Vsc=0, -Vy=0, Vzb=0, V18v=4.7V (this voltage is generated inside the Y-board and goes from Y-main to Z-sus, straight through logic board)

[Hamie]

Re: Plasma tv zenith (lg ?) 60pv220 works 10 min and shuts down

On the PZ950 you can disconnect the z-sus and the tv will run and show an image. See if it brings the picture back.

[anibal2100]

Re: Plasma tv zenith (lg ?) 60pv220 works 10 min and shuts down

Has been more than an hour and the sound still holds.
Now after cycling (on-off) there is only sound, no image.
Turn it off, disconnected Z-sus, no image just sound.
Still thinking control board (logic) is failing..
I'll let cool to see if it comes back and use air heater over the logic board..
Do you think is a way to go ?

[anibal2100]

Re: Plasma tv zenith (lg ?) 60pv220 works 10 min and shuts down

Thank you guys for your time and help. No luck with heater over ctrl board. I'll order a new control board as a final try. I'll post results.