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Old 03-01-2022, 04:23 AM   #3164
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Default Re: Power supply build quality pictorial. part 2

So i was cleaning some stuff up, and dug up this busted PC power supply i found in the trash some years ago, and thought i would get some photos of it before i part it out, so here it is, i don't know the brand or wattage, and i'm not really bothered to look it up, due to what i stated above.

Anyway, here is the board overview, and you can probably see i won't be bothering repairing it:
Yep, it's in two halves, i could try to bodge them back together, but it probably wouldn't be very safe. The main transformer is a ERL38 or roughly thereabout.

Onto the bottom side of the board:
The soldering doesn't look bad, though i think that's the least of its concerns given the shape that it's in.

Now let's dive into the primary side of things.
So lest start with the input filtering, which consists of two .22uf X2 capacitors, two 2.2nf Y2 capacitors, a single coil, and a big looking common mode choke. In spite of what it has, it seems a bit minimalistic to me, but who am I to judge. After that, we have a GBU4J 4A amp bridge rectifier, and a pair of Ltek SM 390uf 200v capacitors.

The main switchers are a pair of IRFBC20's, and the 5vsb appears to be switched by a chip marked 1004BL, which i can't seem to find much about, but i assume it's a somewhat standard all-in-one switch mode controller.

Now onto the secondary side of this thing.
So to start off with, the 5vsb is fed into a SB560 diode, before being filtered by a Nichicon PJ 1500uf 10v capacitor, a small pi coil, and a Nichicon PJ 470uf 10v capacitor. The 12v output is fed though a STPR10 diode bridge, and gets the bare minimum when it comes to filtering, since it only has a single Ltek LZG 1000uf 16v capacitor with not further filtering. The 5v output goes through a STPS20 diode bridge, and is filtered through a Ltek LZG 1000uf 10v capacitor, a pi coil, and a 680uf 10v capacitor. The 3.3v output is fed though another STPS20 diode bridge, and is filtered though a 1500uf 10v capacitor, a pi coil, and a 1000uf 10v capacitor (all Ltek of course). And the -12v rail (which appears to be derived from the 3.3v rail if i'm not mistaken), is filtered through a 680uf 25v capacitor, before being fed through a KA7912 negative voltage regulator, before being filtered though a 100uf 25v capacitor.

The 16-pin chip on the output is yet another chip i can not find info about, but its number is 1002DS, and is likely the supervisor/protection IC for this thing. But that's pretty much it in regard to this thing, it looks like it may have been an okay PSU at one point (assuming it was rated for at most 250w), but the physical damage to the PCB makes it nothing more than a donor for other power supplies. Besides, i have many more PC power supplies that i've found in various places (mostly at thrift stores and in the trash), so not really a major loss to me anyway.

Last edited by RukyCon; 03-01-2022 at 04:32 AM..
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