EAY60968701 power supply schematic needed

[paulstef]

That's from a LG Plasma.

It's not the parts they sell as repair kits.
I followed the procedure in the training manual. Page 41. RL_ON works, then after applying 5V to M_ON it turns on VS, VA and M5V and turns off. Then it cycles doing it over and over again. There is a load on VS as suggested.

If someone has a schematic that would be helpful.

As I said the parts from the "kit" (Fuse, resistor, IC301, diode) are ok. I checked ALL electrolytic caps. They seem to be ok.
All voltages are within limits, VS, VA, 5V, VSTBY, VBOOST etc.

Thanks

[paulstef]

Re: EAY60968701 power supply schematic needed

This is an intermittent fault. It is not temperature dependend. Sometimes it just stays on.
It's not sensible to mechanical vibration etc either.
Weird.

[paulstef]

Re: EAY60968701 power supply schematic needed

Does anybody know what the differences are between the 3 white resistor version and the 2 white resistor version of this board? Are they interchangeable?

[joshbsg]

Re: EAY60968701 power supply schematic needed

I am having a similar problem with this same set.
I am getting all voltages except 'AC DET' Which explains perfectly why it is shutting off right after turning on.

How can I determine the exact issue? I have found IC701 on the rear side but no idea where to check if it is receiving the signal to send to D813.

[paulstef]

Re: EAY60968701 power supply schematic needed

From what I understand is if the mainboard is connected to the PSU and turns it on and THEN there is no AC det the mainboard will shut it off. Their description is a little bit confusing. In some training manuals it even gives the impression as if there were two IC701, one on the PSU, one on the mainboard.

IC701 on the PSU is a microprocessor which doesn't make things easier.

My boards do not turn off after exactly 10 seconds as per their description but randomly.

I ordered two of these IC701, if that doesn't work I need to search further.

Keep us posted if you find something.

[joshbsg]

Re: EAY60968701 power supply schematic needed

If I had a schematic I would start with seeing if the IC is receiving its signal. If so, the IC is bad. If not, its a problem with the rectifing circuit (my guess). Im guessing the IC is never getting the 4.44 to send to the mainboard but I dont know where that voltage is collected at. No info in the manual.

One other thing I was thinking. Is it possible to send around 5 volts to the mainboard on pin 16? That would satisfy the main microprocessor and in theory the set should still function. Even though the PSU isnt making the AC DET the mainboard would be satisfied. Possibly bridge 5volts from another pin on P813?? Whats you thoughts?

[joshbsg]

Re: EAY60968701 power supply schematic needed

The 2 resistor board has to 22 ohm 5 watt the 3 resistor board has 3 10ohm 2 watts if that helps. I do not know if they are interchangebale.