eBay Bench PSU - Common Weakness?

[ssashton]

Hi Everyone,

I have this bench PSU I got on eBay. I'm sure it's a very common model.

It has broke twice! First it popped the P75NF75 and now it has popped both IRF840.

All I did when it popped the IRF840 was reduce the current limiting to minimum while open circuit. Then fizz and a bit of smoke.

Is there any known weakness in this design that I can improve?

Thanks!

[mawyatt]

This looks like the one I have.

Mine has so much output noise it's almost worthless for anything useful. I tried to add some filtering on the output but didn't help much, then found out that it puts out so much noise back on the AC input that it corrupts everything else around

Real POS 

Best,

[HB9EVI]

cannot say anything about general weaknesses, but the noise problem could be solved with common mode choke right before the DC outlets.

also on the AC side is likely missing a CM choke, even though one is visible; it seems to be the usual minimalistic construction where all non-function-related parts are missing; already the AC outlet looks very flimsy wired up.

[rvalente]

AFAIK the best rugged, easy to fix, easy to find, can handle a bunch of abuse and won't give on you are the older HP 61xx and 62xx and 64xx.