PC Power & Cooling Silencer 750W SLI only 0.10v on Green wire.

[nubie]

I have an old PC Power & Cooling 750w EPS12V SLi power supply with the 80mm fan that is unresponsive except for the 5v Standby.

Green wire has 0.10v on it. Will not start PSU when shorted to ground.

There is an ICE2A0565 running the PSU and a
HY510N 'watchdog'.

Does anyone have schematics or an idea of where to start with this guy.


5VSB is at 5.06v connected to Motherboard. There is a 7805 and a diode running the 5VSB it seems.

[Per Hansson]

Re: PC Power & Cool 750 SLi only 0.10v on Green wire.

You could try chipping away the glue that is on the control IC's and nearby resistors.
In your case it looks fine on the outside but it very commonly becomes dark in color and that causes it to become conductive...

If that does not help trace the green PS_ON cable to see where it goes, probably something near it is bad, usually it is pulled up to +5VSB so if it is low something is pulling it down.
That said realistically the power supply should start when the green wire is at 0.1v so something does not sound right...

P.S: ICE2A0565 is only for the 5VSB standby power supply, there is a UCC28515DW PFC & PWM controller on the primary side that controls the main power supply.

[stj]

Re: PC Power & Cool 750 SLi only 0.10v on Green wire.

a full pcb picture would be nice

[nubie]

Re: PC Power & Cool 750 SLi only 0.10v on Green wire.

You could try chipping away the glue that is on the control IC's and nearby resistors.
In your case it looks fine on the outside but it very commonly becomes dark in color and that causes it to become conductive...

Thanks for the heads up on the glue. In person it is quite darkened in my opinion.

If that does not help trace the green PS_ON cable to see where it goes, probably something near it is bad, usually it is pulled up to +5VSB so if it is low something is pulling it down.
That said realistically the power supply should start when the green wire is at 0.1v so something does not sound right...

That will indeed be my next step. The glue is highly suspect so I will do both.

P.S: ICE2A0565 is only for the 5VSB standby power supply, there is a UCC28515DW PFC & PWM controller on the primary side that controls the main power supply.

Aha! I will not worry about it then.

a full pcb picture would be nice

I agree! I snap these up when I can find them for ~$20 because they really deliver enough power to run 3 systems (Or one current gen video card XD) My first one ran a Q8300 overclocked by quite a lot on a Scythe Infinity Mugen! This is the first one that failed to operate for me, they are usually bulletproof (IE the nameplate rating is the continuous rating at 50C)

[nubie]

Re: PC Power & Cool 750 SLi only 0.10v on Green wire.

a full pcb picture would be nice

After scratching off some of that glue and running it out of the case I'm now getting 2.5v consistent.

There is UCC28515DW on a daughterboard in one corner.

[Per Hansson]

Re: PC Power & Cool 750 SLi only 0.10v on Green wire.

After scratching off some of that glue and running it out of the case I'm now getting 2.5v consistent.

Nice, so does it work now?
P.S: Check soldering of the green cable, it possibly looks bad on the underside of the PCB...
If it does not work post a closeup of that area of the PCB with good lighting so the traces can be followed.

[nubie]

Re: PC Power & Cool 750 SLi only 0.10v on Green wire.

Nice, so does it work now?
P.S: Check soldering of the green cable, it possibly looks bad on the underside of the PCB...
If it does not work post a closeup of that area of the PCB with good lighting so the traces can be followed.

Still the same symptoms: dead as a doornail. The green wire seems to go to the HY510N chip, which then sends a signal through the optoisolator just fine (15v IIRC) and that goes to a transistor underneath the other side of the board. I'll try to trace that out.

I'll look at the green wire again, but it has good continuity to the HY510N.