I'm trying to modify this psu (Diamond 500w)

[370forlife]

Re: I'm trying to modify this psu (Diamond 500w)

Check for any solder whiskers or bridges you may have inadvertently created.

About the 200V 16A schottky, I have a keerda ATX-3000A (logisys 575W) with a very similar design to this which had a 200V, 30A Fast Recovery type on the 12v. I replaced it with a 60A, 45V schottky, and it worked just fine. Infact, etnietering has a logisys-keerda based off the same design that had an identical 16A, 200V Fast Recovery type on the 12v, and he tried replacing it with a 20A, 250V Fast Recovery type, and it tripped the short protection. He replaced it with a 60A, 45V schottky from ONsemi, and it worked fine after that.

[forza764]

Re: I'm trying to modify this psu (Diamond 500w)

Well, i cleaned the best i could, and still...no start.

The +5vsb reads 5.01 volts, between +12 and ground i get 43 ohms.

To the side of the x cap i installed, there was a jumper J1 i didn't remove, i don't know if that is causing problems.

[etnietering]

Re: I'm trying to modify this psu (Diamond 500w)

J1 is necessary, it gets half the AC wave to the bridge rectifier. 370 is correct about my Logisys/Keerda unit. Completely baffling...
Check for shorts between the other rails and ground, as well as across the output diodes.

[forza764]

Re: I'm trying to modify this psu (Diamond 500w)

Problem solved.

The mospec f16c20c was missing a plastic washer in the screw, lol.

In this last test, at first the psu lasted like one second on, then shut off. When connected to an old mobo, it started ok.

+12v - 12.01v
+5v - 5.01v
+3.3v - 3.32v
+5VSB - 5.01v

[etnietering]

Re: I'm trying to modify this psu (Diamond 500w)

Yup that'll do it...glad you got it working though! Those voltages look great! Some power supplies won't start if there isn't enough load. That's probably why it wasn't starting with just the CD drive.

[forza764]

Re: I'm trying to modify this psu (Diamond 500w)

I'm recapping now, but i have a question, ¿is ok a Rubycon 6.3v 3300uF for the 5v rail?

[etnietering]

Re: I'm trying to modify this psu (Diamond 500w)

It should be alright. If you have 2 places for it (one before the inductor, and one after), put it after the inductor. The voltage here will be much smoother, and less likely to have spikes over 6.3v.

[forza764]

Re: I'm trying to modify this psu (Diamond 500w)

Psu semi-recapped and almost ready for another test.

Almost all caps in the secondary are Rubycon's from a Sega psu, except two KZG from a mobo, and one Teapo for the 5VSB.

I also added a .47uF x-cap and a on/off switch to the case. Next time i'll see if i can find a good schottky for the 12v and good caps for the primary.

I wonder if this psu is ok for the following pc:

Amd Athlon x2 2.2 ghz 65w
2gb ddr2 800 mhz
Foxconn micro-atx mobo
Ati Radeon HD 4670
Dvd-rw LG
Maxtor sata 200gb
92mm case fan

What do you think?

[stj]

Re: I'm trying to modify this psu (Diamond 500w)

those sega sourced caps may be almost gone,
if they are from a saturn or dreamcast, i have to recap those a lot because of aging.

[370forlife]

Re: I'm trying to modify this psu (Diamond 500w)

It may be alright for that pc if it weren't for the video card. I wouldn't recommend running this psu for a long period of time, good for things like testing pc's, temporary in a low power computer, thats about it.

[forza764]

Re: I'm trying to modify this psu (Diamond 500w)

Well, then i guess i will only use this psu for testing pc's.

Last test:

+12v - 12.01v
+5v - 5.02v
+3.3v - 3.33v
+5VSB - 5.00v

Thanks for the assistance!!!