the gutless, bloated, and fried power supply hall of shame

[RukyCon]

I may actually try putting slightly beefier parts on the secondary and put this PSU into some junker PC that I plan on throwing together out of spare parts (just so I have something at my workbench for looking stuff up while working), and then I can see how many years, or (realistically speaking) months or weeks this thing lasts before giving up the ghost. Though, I won't be wasting any of my 'good' parts on this.

Originally Posted by momaka

What? WHAT? ... WHYYYY?!

Yeah, that was more or less my exact reaction when I saw that they used a 30A part for a rail that is rated for 2.5A max, but as you mentioned, the part could be a QC reject that Leadman desperately wanted to reuse. I do plan on trying to test the side that had its leg cut off, to see if that side really is defective.

Originally Posted by momaka

No, they (Powmax / Leadman) actually got that part right... as if by a miracle.

I guess that's my PSU design lesson of the day.
But seriously, I do appreciate you going out of your way to explain that to me, as i'm pretty much fully self-taught when it comes to electronics like this, so this kind of info is the type of stuff i may normally not find online, at least not easily, so thank you.

Originally Posted by momaka

It WAS worth it - you saved someone else $8 from buying this POS... plus who know how much headaches for them, if they aren't as well-versed in electronics/PSUs/computers as you are. For all you know, you could have saved someone's really important data or only computer from blowing up / burning out when this PSU goes out. It may seem strange to think of it this way... but that's what it is, really.

I hadn't thought about it that way, but now that you mention it, it makes sense, as if i didn't grab it, someone else would have, which is what i think happened to the Rhino SP-450Y PSU i found in the trash back in 2018, since it had a Savers price tag on the bottom of the unit, which says that it was sold at a Savers thrift store, only to be bought, and do who knows what to someone PC (hopefully nothing, but it's hard to know for sure).

Speaking of Savers, I actually picked up a couple PC PSUs from a local Savers recently, one of them needs a bit of work though (a full recap of the secondary).

Oh, and I also got a good chuckle or two out of the design of this PSU, which makes it slightly more worth it to me.

Originally Posted by momaka

(Yes, don't try using this PSU at all is probably what should be meant.)

Fixed that for ya.

Originally Posted by momaka

Do any of the cables have a valid UL number or other certificate number? If not, I'd consider the ratings on them at least somewhat questionable - particularly the voltage one.

Actually, none of them do, even the "18AWG" ones lake any safety markings, also, i double-checked the "18AWG" wires again, and found that they're slightly closer to being 19AWG, since they're still thicker than some true 20AWG wire i have, but not quite thick enough to be 18AWG.

Originally Posted by momaka

At least with this unit you didn't get the cheapest crap heatsinks, though, unlike this Sun Pro KY-480ATX.

I actually came across that post not too long ago, and i remembered that a (now defunct) electronics surplus store in my area had a box full of bare PC PSU boards, all of which looked more or less exactly like that Sun Pro PSU, all the way down to the paper thin heat sinks. How did they get so many, and without the cases, i don't know. I may have taken a few photos of them, but i'll have to see where those photos ended up.

[dmill89]

Originally Posted by momaka

4th... and I have to concur with Dan81 here: I don't think this PSU was made or designed by Topower. The label is indeed likely a BIG lie. The "LP" markings on the transformers and the PCB suggest Leadman Power - a.k.a. Powmax / Sun Pro. This is hands-down my least favorite PSU manufacturer... or most favorite worst manufacturer, I don't know anymore. If it was a Topower unit, those usually have "top..." or "ever-power" text on the transformers.

I guess "Marketed by Topower" doesn't have the same ring to it. Zumax was Topower's "budget" line, but it looks like at least with this unit they just farmed the whole thing out and Topower's involvement was likely limited to slapping a label on it and putting it in a box.

[Dan81]

I doubt Topower had anything to do with the label, if at all.

[RukyCon]

So here is a power supply that i found in the trash, the PSU appears to be rather old judging by the external switch and minimal output leads.

Label:
IMG_20220609_222204[1].jpg
Looking at the label, we don't really get much info about the PSU, other than its a 230w unit, and that i shouldn't be taking it apart in five different languages, but that ain't gunna stop me cuz i can't read most of them.

Anyway, here is the forbidden insides (AKA, the board overview):
IMG_20220609_221715[1].jpg
IMG_20220609_221704[2].jpg
Well, there isn't a lot to see in here, and TBH, i was kind of suprised when i saw how empty it was inside, mainly because this PSU had a bit of weight to it, but as it would turn out, most of that was in the (suprisingly decent) case this board was placed in. Also, we finally find a proper name and model to go to this unit, Moretec. Now i couldn't find much about them, but the few things i did find were supringly decent, so it's a shame that they stooped so low for this unit, but maybe it could be salvaged.

Primary side:
IMG_20220609_221724[1].jpg
So in terms of input filtering, it has no input filtering, not even the usual fake Y-class capacitors, we do however, have an NTC themistor and a fuse, a rather cheap looking fuse, but a fuse none the less. The bride rectifier is made up of 4 1n4007 diodes, i want you to look at how tiny and under-rated they are, i mean, they're 1 amp parts, and if this is a 240w PSU, then they would possibly be seeing up to twice their rated current under full load (at 120V, assuming 100% PSU effenicy, which is highly unlikely to be the case), and even at something like 75% load, they'd still be getting overloaded. Now the main capacitors are a pair of Rubycon YKs, rated 220uf, 200v, in which they test at 215uf and 225uf respectivly. They appear to be real Rubycons, which would probably make them some of the best quality parts in this PSU. The main switchers are a pair of (2S)C2810s in a standard dual-foward configeration. The main transformer is 33mm wide by about 29mm tall.

Secondary side:
IMG_20220609_221733[1].jpg
The filtering for each rail is a follows:
12v: 2x PR3002 (100v, 3A) fast recovery diodes (mounted in a classic diode bracket configeration), Pi Coil (16~18 AWG, 20 turns, 5mm core), Luxon SM 1000uf, 16v capacitor.
5V: S10C40C (10A 40V) schottky rectifier, PI coil (12 AWG, 8 turns, 5mm core), 2x Capxon KM 1000uf 10v capacitors locaded on either side of the coil.
-12V: 3x PR152? (obstructed part number)(1.5A) fast recovery diodes, Capxon KM 470uf 16v capacitor
-5V: 2x PR152? fast recovery diodes, Capxon KM 470uf 16v.

The controller chip is a (TL)494CN, beyond that there,s not much else to note.

The Fan:
IMG_20220609_221749[1].jpg
Just an older Yate Loon fan, still spins really well.

I'm not really sure what to do with this thing, maybe it might be worth beefing up a tad bit for projects and such, but i don't know.

[Dan81]

I would beef it up a bit and keep it should you ever find the desire to build an retro AT machine.

Maybe a personal preference but I would rather put 2-4 hours of work in beefing up an AT unit (which I did to an Essun 200W AT PSU) than having to fiddle with an adapter and an ATX PSU.

[PeteS in CA]

The model number suggests it's a 200W/150W power supply (or maybe the PCB is used for 150W and 200W models). Anyway, the 220uF input caps are about right for 150W. Based on possible clues in the S/N and numbers on the magnetics, I'm going to guess the power supply is 1996 vintage.