FSP300-60GLS overheating problem

[Behemot]

Oh man! Just when I NEED these units fast and I don't really have the time to waste for one not working, one is not working! The GLS is basically a scaled-down version of Blue Storm II (GLN).

Just did full recap and one of these is behaving like it is overheating: after a wile on the load, the voltages start oscillating and than it turns off. The stand-by is at stable voltage the whole time. If I turn it on again it happens within a few seconds. So definitelly an overheating problem. Any idea what may the problem? Fan controller? As far as I found, this has no OTP.

When something is too hot inside, it even does nto want to turn on for a while.

[stj]

Re: FSP300-60GLS overheating problem

did you remember FSP like to hide a couple of small caps in black sleeving?

[Behemot]

Re: FSP300-60GLS overheating problem

Two crapxons KF 1000/16, both replaced. The input caps seems OK too (have not replaced this one).

It is actually strange as it seems it is maybe not fully temp dependent. Or at least not surface. Sometimes it behaves like dying animal - starts making mess, voltages drop to like 1/3 of nominal, oscillate till it finally turns off. But that it twists a few times, sometimes even for a few seconds. The same is happening even when I turn everything on my load off, only keep the fans running (about 28 W). With such low load, anything on the surface should be OK. I am thinking maybe it really is shorted transformer this time? I noticed it was running quite hot…it would make sense, the transformer heats internally.

Otherwise I checked it twice already, nothing wrong visually. Resoldered couple joints but still nothing.

[stj]

Re: FSP300-60GLS overheating problem

failing diode?

maybe freezer spray would help.

[CapLeaker]

Re: FSP300-60GLS overheating problem

or some resistor going high in value while under load.

[Behemot]

Re: FSP300-60GLS overheating problem

Well yeah, which one? There are tens of those things…

[CapLeaker]

Re: FSP300-60GLS overheating problem

also could be a cold solder joint on the inductors of the secondary. You need to probe around with the oscilloscope and see if only one voltage rail or all of them going nuts (not the STBY voltage).

Which one? I dunno... didn't see the PSU or a schematic. Start at the mosfet driver and the feedback circuit. I posted some switching PSU repairs here on badcaps. There was a cold solder on a inductor, a bad voltage dropping resistor that went high in value that fed the Mosfet driver, a bad cap on the feedback circuit etc, just for ideas.

[Behemot]

Re: FSP300-60GLS overheating problem

I resoldered the 3.3V inductor, the rest seems OK…

[Behemot]

Re: FSP300-60GLS overheating problem

Tiny update. I've let it run just with the fans. It is so low load nothing inside should get anything but warm in worst case. Problem also appeared, just later. I do not think it is heat, or heat alone.

I also checked the voltages, all output rail were down (+3.3 V was higher but there was no draw from it, with 1.5 A draw it dropped quickly). The Power good signal dropped out as it should so at least the supervisor is somewhat working.

[Behemot]

Re: FSP300-60GLS overheating problem

Got another troubling unit, this time the SB does not work at all. Think I will use one as donor and try replacing components one by one to see what happens. Starting with DM311 maybe?

[CapLeaker]

Re: FSP300-60GLS overheating problem

You should be able to make out of those two one working unit no problem.

[sam_sam_sam]

Re: FSP300-60GLS overheating problem

Got another troubling unit, this time the SB does not work at all. Think I will use one as donor and try replacing components one by one to see what happens. Starting with DM311 maybe?

Did you get any where with this power supply ?

[Behemot]

Re: FSP300-60GLS overheating problem

Not yet, it has low priority right now.

[harii07]

Re: FSP300-60GLS overheating problem

Hello all, I am about to repair FSP460-631U SMPS. I need service manual or circuit. Any on have this or any direction. Please