LG 50pq3000

[bill25]

Re: LG 50pq3000

The relay clicking all the time (every time i put the TV on) and voltages is 380v without the resistor.

[bill25]

Re: LG 50pq3000

The voltage on pin 5 on the IC is 4.8v

[dick_barton]

Re: LG 50pq3000

So the supply to the micro is fine. I don't know how you would test it since it appears to be a supervisory IC monitoring various signals to control the power supply.

[bill25]

Re: LG 50pq3000

It's difficult to see if it works properly but i wonder, can i change it with a new one? or is programmable from the factory (LG).

[dick_barton]

Re: LG 50pq3000

Being a micro I can only assume that it is pre-programmed for that set.

[R_J]

Re: LG 50pq3000

The relay clicking all the time (every time i put the TV on) and voltages is 380v without the resistor.

So with the power supply completely disconnected except for the ac mains, the relay continues to click when power is applied?
The 380v would suggest the pfc is working and getting the vcc2 voltage.
That ic701 is pre programed and not likely the problem.
There are 3 large white ceramic resistors R957 etc. check that they are ok.
Can you read the number on IC801?

[bill25]

Re: LG 50pq3000

The relay click once on start up. Resistors are good i check them first. I replace the IC801 already. (L6599D).

[bill25]

Re: LG 50pq3000

The relay click once every time, i start the TV.

[R_J]

Re: LG 50pq3000

What is the vcc voltage on Pin 12 of ic801?
What is the voltage on Pin 5?
Why was the ic replaced? was it bad or just a suspect?

[bill25]

Re: LG 50pq3000

No its not bad l have a new one and checked.
Pin 5 - 0 volts
Pin 12 - 0 volts.

[bill25]

Re: LG 50pq3000

If you have schematics from this PSU please upload it.