Prima PH4237P 42" Plasma Power Supply

[Sevenqi]

The TV power LED turn green less than a sescond then turn red again.
The power supply board part # is 782-PS42FK6-20A, the led in side the board keep flashing in red.
I tested the Va is 60 V, looks normal, but the VS is only 62 V, I believe it should be 180V.From what I understand, the protection circuit triggers to detect the low Vs voltage. I adjusted the voltage variable resistor, but the Vs output is still no change. Any idea how to make the Vs output back to normal?

[tom66]

Re: Prima PH4237P 42" Plasma Power Supply

Check that the Vs potentiometer is clean, and all resistors in the divider are good. I suspect you have some excessive load on Vs - tried without sustain boards?

[Sevenqi]

Re: Prima PH4237P 42" Plasma Power Supply

I discoonect all the boards and tested the Vs when I press the power button, the same as 60v, it only lasted for less than a second then went to protection mode.

[tom66]

Re: Prima PH4237P 42" Plasma Power Supply

If you adjust Va, does it affect Vs too? BTW, that is a poorly built plasma power supply. They are usually built better than that.

[Sevenqi]

Re: Prima PH4237P 42" Plasma Power Supply

The Va has its own potentialmeter to adjust the voltage, it works independantly, so not affect the Vs, they are in different sections.

[tom66]

Re: Prima PH4237P 42" Plasma Power Supply

The Va has its own potentialmeter to adjust the voltage, it works independantly, so not affect the Vs, they are in different sections.

What I am trying to judge is if the Va is adjusted does it affect the Vs, maybe there is a short between the supplies.

[Jriggs2k]

Re: Prima PH4237P 42" Plasma Power Supply

Hello,
I have the same TV with the same issue and same readings.

All the CAPS look good, no bulges yet the power on VS is only 60v no matter what is connected, or not, to it.