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Old 04-20-2022, 10:15 PM   #3186
A Fake Rubycon
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Join Date: Jan 2017
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Default Ultra ULT-500P

Well, since my last project isn't working out how i hoped it would, I thought i would take a look at another of my PSUs that needs some repairs. In this case, an Ultra V-Series 500w PSU i found for $10 at a Savers thrift store.

Now unlike every other used PSU i find, this one still had its retail box despite being used, and came with just about everything minus the mains power cable.
Now another thing about this PSU was, the case had been opened up, and the fan was loose inside the box, but it did not appear the last owner had done anything to the board itself, because if they had, then this thing probably wouldn't have been worth trying to repair.

Anyway, here is the PSU label:
Not much to say here, but judging by the UL number, this PSU appears to have been made by Wintech.

Board Overview:
So a few things are clearly off here, the most obvious thing being the secondary caps are nearly all dead, but also, it appears something had been spilled onto the board, and had been allowed to pool up around the lower-right corner of the board. The heatsinks appear to be decently sized. And on the bottom of the board, there is a model number on it of WIN-450WP. Now it seems like this PSU board may have originally been designed for a 450w PSU, so it seems a bit sketchy to push the board to 500w, but that might just be me.

Primary Side:
So for input filtering, we have three .22uf X2 capacitors split between the main PS board and a separate filtering board, two common mode chokes, and two sets of 2 4.7nf Y2 capacitors. The rectifier is a RS805 (8A, 600V), and the smoothing capacitors are a pair of JEE 820uf 200v caps, both of which test at roughly 760uf. The main switchers are a pair of 2SC3320 transistors in what looks like a dual-foward configuration, and the 5VS/Aux switcher is a C3866 transistor in a two-transistor configuration. The main transformer is roughly 40mm x 40mm.

Secondary Side:
The filtering for each rail is as follows:
5VSB - SB540 (5A, 40v) Schottky Diode, 2x Canicon 680uf 16v with a PI coil between them.
12V - 2x F12C20C (12A, 20V) Fast Recovery Rectifiers, Su'scon SD 1000uf 16v, PI coil (4mm Core, 10 turns, 14AWG), and a Su'scon SD 2200uf 16v.
5V - S40D45C (40A, 45V) Schottky Rectifier, Canicon 3300uf 10V, PI Coil (5mm Core, 7 turns, 14AWG), JEE 2200uf 10V.
3.3V - SBL3040PT (30A, 40V) Schottky Rectifier, Canicon 3300uf 10v, PI Coil (4mm Core, 10 turns, 14AWG), JEE 2200uf 10v.
-12V - FR154?, PI Coil, Canicon 680uf 16v.
-5V - 2x FR154?, PI Coil, Canicon 680uf, 16v.

Of all of the main secondary capacitors, only three appear to have not failed yet, those being the Canicon 680uf 16v cap on the -5V rail, and the two Su'scon caps on the 12v rail, all of the smaller capacitors (except for one) are all Canicon, and a few appear to have been baked, judging by the fact their sleeves have turned a yellowish brown, though next to a couple of these baked capacitors is the only non-Canicon tiny capacitor (Su'scon SK 0.22uf 50V), and its sleeve is still bright yellow, which might say that the Canicon sleeves are just crap (just like the capacitors )
The controller chip is a KA7500C PWM IC, paired with a SG6510D1 supervisor chip.

And lastly, the fan.
Not much to say about this fan, other than the fact it's totally seized up, but i didn't notice that until i was trying to test the PSU and noticed that the fan wouldn't move, despite getting the PSU to turn on, the PSU itself was also very whiny when i powered it up, and that was with no load on the output, i assume the failed capacitors have something to do with it, but i guess i'll have to recap it and see.
Also, this happens to be my 666th post O-o.

Last edited by RukyCon; 04-20-2022 at 11:04 PM..
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