Introducing... the POS-124Z which really is a POS:

Yep it's a POS allright.

I tried powering it up. It's a KILLER - not fried, but sure will fry things! I got 21V out of it unloaded according to my DMM!

I tried 21W load (car lamp) - got 16V, which is really pushing that lamp.

Then I tried a 50W load (car headlight) - got 13.2V. Not too bad but this is with the heavy load...except the circuit breaker kept tripping.

So I had to take a peek:



EIEW. Looks like a Darlington emitter follower + Zener device. Heatsinking?...

Back in 2020 i bought a (2nd hand) compact ATX psu to replace my current one. My PC case only fits very short ATX power supplies so i didn't really have the choice of buying a decent 80Plus unit. The current unit is a modded YoungYear unit that i made a thread about a while ago:
A "nice" YoungYear unit? - Badcaps

The "new" unit is a KDM-M6480 480W psu, the 480W number is a typical KDM bullshit claim of course, but the 24A rating on the 12V rail seemed reasonable and the "Active PFC" claim gave me a bit of hope that this was going to be decent-ish....

When my dad asked me to 'fix' his battery maintainer he knew they were fix able cause someone 'fixed' his old one a long time ago, well here i am holding this 'old' one, it belongs in a museum, i assume what few parts are quality ones cause this was from the days when people used quality stuff, i guess quality and design are very different things

This think has absolutely no regulation

I found 2 diodes in the bottom of the box just laying there
This thing appears to have 3 components
1 diode (assuming 1 is the old one, or the guy just dropped one and did...

Hello Again, so i'm bringing back this Zumax PSU from the gutless thread and going to be doing some modifications, and also putting it into a PC i'm going to throw together out of spare parts to see how long it lasts.

So the first thing i did was fill in the missing filtering, by replacing the cheap common mode choke with a real one and adding a 470nf X2 capacitor in the open capacitor spot, i then replaced the fake Y-class capacitors with real ones, i also swapped out the mismatched primary caps with a pair of Aishi WK 470uf 200v caps, both of which test around 520uf. I also swapped...

Looks like I may need a little help from the PSU experts (or anyone really! ) I have a Corsair CX750M (Model 75-002019) that I picked up for free about 4 years ago. This is the PSU:



So here’s what’s strange about this one: it appears to work normally (normal output voltages) and any PC is stable with it. However, after a while (typically 10-20 minutes, but time can vary depending on the load), there is a sweetish smell of burned magnet wire insulation emanating from the PSU. Upon opening the PSU after this happened (many times), I was able to confirm...