Re: Replacement caps for Antec SP-450?

So a couple of years have passed since I sorted out my SP450 (see my previous posts in this thread). I meant to wrap up back then, but better late than never. Unfortunately the motherboard in that system failed a couple of weeks after the PSU. A capacitor had clearly vented, but on closer inspection a number of capacitors on the board were badly bulging after it had been fed nasty power from the SP450. I replaced 8 capacitors on the board and it went back into service. Both the SP450 and the motherboard are still in service today!
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Re: Replacement caps for Antec SP-450?

Any expert insight into why the resistor and zener could have gone?

I didn't get much out of tracing the extra part of the circuit connected to the failed cap EC5. I have very little experience of this kind of circuit, so it is difficult for me to see what is going on. It is clear that if ZD5 were to go short circuit, then R11 could dissipate excessive power, but I don't know if failed capacitors in other parts of the circuit could cause ZD5 to fail.

@Toasty: if you have C4, would you be kind enough to measure...

Re: Replacement caps for Antec SP-450?

Toasty, you are right, those designations got a bit mixed up. An edited schematic is attached. IC1 was actually 1C1, and is presumably the capacitor next to IC3. The real IC1 is the opto.

Some more schematic attached: underlined means SMD

Trace side image attached: Marker pen and link wire are not original

EC5 had dried up and measured 0.04uF...

Re: Replacement caps for Antec SP-450?

It looks like my board has additional PFC circuitry. I have traced out some of the circuit and attached it. If you don't have IC1 and IC3, then I'm guessing you don't have the large choke L1 either (see attached photo). Also note on my diagram: R38 and R39 are sleeved with heat-shrink, so I can't read the values, but they measure less than the resistance of my meter probes.

As Toasty had guessed already, R11 looks like a current limiter. I'm guessing a lowish value which will not be critical. I have attached the datasheet for...

Re: Replacement caps for Antec SP-450?

Sorry to resurrect an old thread, but it seemed like the most appropriate place. I have a SP-450 from a Sonata II case that recently died. It is amazing it lasted so long - I got it 2nd hand and have been using it for over 5 years. There were obvious signs of electrolyte leakage on several of the fuhjyyus.

Anyhow, in addition to some capacitors, a resistor and a zener diode on the primary side had failed. The resistor had burnt the PCB badly (see photo), and the zener was acting like a short. I was able to get a replacement zener...