Old Fortron FSP250-60GTM

[Behemot]

Re: Old Fortron FSP250-60GTM

I used KZG's for output and KMG's for small capacities. Two 330uF KZG's used for output, too (for -12 and so). As I said, I'll watch them from time to time and maybe sometimes borow ESR meter...

[c_hegge]

Re: Old Fortron FSP250-60GTM

They may be OK for now, as long as they are cooled well enough. Just keep an eye on them

[Behemot]

Re: Old Fortron FSP250-60GTM

Yeah the fly resistor mod should keep them cool...

I even mounted the resistors on main heatsink in the second Fortron today (the FSP-300GT one), this one has fan controller and they would burn comonents around them with fan in slow mode.

[momaka]

Re: Old Fortron FSP250-60GTM

I applied the glue on top of the coil, I won't be able to get it under it, it's impossible

That should be fine then .

The sound is coming from the PSU only when it's turned on and it varies according to load. That's what leads me to main transformer.

I think you might be right then. I re-read you first post and noticed that you said the PSU whistled even before the recap.

I get exactly the same 5.22 volts even when the PSU powers the motherboard. And yes, as I wrote, I replaced every single one electrolytic capacitor.

That's strange. Changing the critical cap on 5vsb *usually* makes the voltage normal. Samxon RS and Chemicon KMG are good choices for the small caps too. You said it was 3.6v before the recap, correct? I'd definitely look into it. A faulty 5vsb can kill a motherboard. Just search for Bestec ATX-250 12E on here if you need examples .

As for the caps, I believe ESR is not the problem - e.g. Samxons RS have much lower ESR and they are actually meant for power supplies. Are not caps in PSU's almost only low-ESR ones anyway? I've been quiet surprised when I saw recommendations of caps which usually are in VRM's on motherboards as a replace for failed caps in PSU's.

Samxon RS are actually an excellent choice for PSUs since they are low ESR, but not too low. On the othe hand, Rubycon MBZ/MCZ, Chemicon KZG, and Nichicon HM/HN/HZ have really low ESR and shouldn't be used in PSUs. I know that some people here have done it with no problems, but PSU output circuits are tuned to a certain frequency, so generally it's not a good idea to deviate from the ESR of the original caps (unless of course the original caps were not adequate in the first place, such as what you might find in a really cheap PSU).

On the top of all, I'll let the KMG's there and see...there are definitelly better than bulged OST's and Teapo's now, aren't they?

Absolutely.

once again, what was the reason for them to fail, they did not handle the heat or even the ripple?

Heat more likely. This is how I got a few good PSUs - their fan seized and the caps bulged .

Well, maybe I won't use the PSU to one of my normal computers...maybe I'll keep it for running in oil. I plan it for quite some time now

That would be interesting. Maybe even run the whole computer in mineral oil. I've seen people do it. If you put a Pentium 4 Prescott, you can even use it as a frier .