Samsung 63" plasma turns off in a second

[zape]

Hi
I'm trying to fix the Samsung 63" Plasma TV (model number PN63B590T5FXZA)

The symptoms: TV turns off in a second after turn on attempt.

Initially I suspected the power supply. Vs voltage was raising way too high and probably overvoltage protection was turning it off.
Then I disconnected Y-Sustain board and connected two 40w bulbs in series to the Vs output.
It turned on fine and generated correct Vs and Va voltages.
It appears that the power supply will not stay on without a load because Vs voltage is rising too high.

So now I suspect a faulty Y-sustain board.
I checked all big transistors and almost all smaller parts like diodes and found no shorts.
When connected to the power supply, it would generate Vscan voltage, that appears to be correct (around -190v)

I also checked the X(Z)-Main board and Vb voltage is present (though 20% higher than specified on the panel)

Any ideas how I can diagnose the problem?
I have an idea to keep both bulbs and Y-Sustain board connected but I'm afraid it will overload the power supply or burn something on the other boards.

[heavymachines]

Re: Samsung 63" plasma turns off in a second

whole point of using light bulbs prevent overload.

[zape]

Re: Samsung 63" plasma turns off in a second

In this case the bulbs are connected to the power supply to put additional load.
I took a risk and turned it on - the TV works just fine and I get the test pattern showing on the screen.

So it has to be something with the power supply. It kind of works, but does not start without additional load on the Vs rail. After it started I turned off the lamps and it works. So the cheap fix solution would be to have a power outlet wired next to the TV to connect two lamps before you can turn it on lol.

[zape]

Re: Samsung 63" plasma turns off in a second

Forgot to update this thread, I fixed the TV
It was one of the smaller electrolytic caps on the power supply board