High-Rely Enclosure PSU (Weihai Power)

[Pentium4]

This thing is from around 2008, and just got used on occasional on site jobs. It stopped powering on anything, but it still gave a strong standby light, and had a horribly loud buzz. It needed to be used so I recapped it, and brought it back to life. I know caps degrade from not being used, do you think that's the main thing that killed them, or maybe that resistor cooked them? When it worked and was running, the exterior didn't feel very hot at all.

[Th3_uN1Qu3]

Re: High-Rely Enclosure PSU (Weihai Power)

Crap caps don't need a reason to degrade. They just do.

[momaka]

Re: High-Rely Enclosure PSU (Weihai Power)

I see a 200 Ohm and a 100 Ohm power resistors on the secondary. Check on what rails they are. I'm guessing the 200 Ohm is on 12V and 100 Ohm on 5V (it would be stupid if it was the other way around... and that's why you should check). With the 200 Ohm resistor on 12V rail, it's dissipating around 0.7W, which IMO is a bit high but not unreasonable like in Deer/L&C power supplies. It's also far away from the caps, so overall I don't think it's the heat from the resistors that caused it.

So likely it was just the caps degraded by themselves. After all, you have CapXon and Teapo. Teapo in a small enclosure is a no-no. And CapXon... well, we all know CapXon is straight rubbish.

Forgot to mention... if there is a loud line buzz/hum, the primary CapXon cap may be bad too. Usually primary caps don't fail, but CapXon has been an exception to that rule a few times.