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Old 03-11-2022, 10:37 PM   #3178
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Default Re: Thermaltake Purepower HPC-420-102 DF

Originally Posted by RukyCon View Post
Nope, it's only one IRFBC20, the other one is a P6NB80.
Good catch!
Sounds about right - IRFBC20 is for the 5VSB (since these are generally low-current parts) and the P6NB80 should be the main PS switch.

Originally Posted by RukyCon View Post
Anyway, here is another PSU that i have, this one (unlike the last one I posted) is going to be fixed up, since it appears to be a well-built PSU (and it wasn't in two halves like the last one).
I concur.
Looks OK for a fix-up.

Originally Posted by RukyCon View Post
not sure what the 'ATX 12V' sticker is supposed to mean (don't all ATX supplies have 12v?)
Well, looks like Per, PeteS, and Dmill already answered that.
But indeed it was just to denote that the PSU had (supposedly ) a strong enough 12V rail for a 12V-based system. In the early 2000's and before Pentium 4 came out, most motherboards used the 5V rail to power the CPU, and this is where most of the load from the PSU was going. Then around 2002-2003, the 4-pin 12V CPU connector started to appear on motherboards - mostly on Pentium 4 motherboards at first, but eventually also on latter-made Athlon XP boards... and it caught on, because it allowed for more power to be transferred to the motherboard without the need for very thick cables.
That being said, PSU manufacturers still kept the strong 5V rail for a few more years afterwards in order to be backwards-compatible with older motherboards. And yet to show that their PSU was also capable of handing new systems, such "ATX 12V" stickers were quite common. Other ones commonly seen were "Intel Pentium 4 - ready", "Approved by Intel and AMD", "Complies with Intel Pentium 4 and AMD motherboards", and similar. In reality, though, only usually the cheaper PSUs had these labels. That's not to say that the PSU you posted is necessarily a cheap one. Some manufacturers just continued to do that well into the mid-late 2000's for some reason (too lazy to re-design their labels, I guess. )

Originally Posted by RukyCon View Post
Some of you may have noticed that something is bodged onto the primary side, and that is a 220pf 1kv ceramic capacitor, and it's hooked right across the drain and source pins of the Mosfet there, i may be wrong, but i'm guessing someone forgot to put a proper snubber in the PCB design, so this is supposed to be a quick fix.
Yes, kind of.
Actually, it's probably more to do with slowing down the turn-On time of the switching transistor on the 5VSB. I've seen this on a few PSU's 2-transistor 5VSB circuits, though it's rare. Indeed it was probably a last-second production floor "fix". I think I even tried removing it on one PSU just to see what happens... and the 5VSB circuit was definitely not happy - regulation all over the place and harsh squealing noises. I did it with an incandescent light bulb in series with the line input, of course... so no damage to the PSU. Just put back the cap in and all was good.

Originally Posted by RukyCon View Post
with the 5VSB/aux switcher being a SSP2N60B Mosfet, which is set up in what appears to be a classic two transistor design.
Yup... 2-transistor self-oscillator it is.

Originally Posted by RukyCon View Post
The main transformer is 40mm wide by 45mm tall, which seems oversized for 420w, but better that than undersized.
It's probably an "ERL39" (i.e. 39 mm). But with the tape insulation an all, it does usually come out to 40 mm measured.
Good to see a large transformer like this. Half-bridge PSUs tend to have slow switching speed of the main PS, so they need more turns for their windings... and thus bigger transformer size if thick windings are to be put inside. This along with the 2SC3320 BJTs makes is a pretty capable PSU - at least on the primary and transformer side of things.

Originally Posted by RukyCon View Post
Secondary side; ...
Right off the bat, I see a green toroid core for the 3.3V rail's output inductor, and a pretty good sized one at that. This is a Micrometals -52 core and definitely good to see (lower losses.) The main output toroid appears standard -26 core, but at least it's still pretty large in size and appears to have a good amount of copper on it.

Originally Posted by RukyCon View Post
12V: MBR30150PT (30A, 150V) rectifier, Teapo SEK 10uf 50v, PI Coil, Teapo SC 2200uf 16v.
I was wondering why this PSU looked somewhat familiar.
The SG6105d PWM IC was already running a few ideas up in my head.
But that cap combo arrangement on the 12V rail is the giveaway here: this is a Sirtec / Sirfa -made PSU. I believe it is a "High Power" series/design.

Here's a similar Jeantech PSU I posted about awhile back:

And to some extent, you can also see the similarities in this Task TK-930TX PSU, also made by Sirtec (but slightly older, dating back to 2003):

That said and regarding the filter caps on the 12V rail - don't change the values too much. For the 10 uF cap before the PI coil, you could probably increase that up to 330-470 uF and not very low ESR (GP 105C is OK)... but I wouldn't go further. Seems the feedback loop doesn't like it otherwise. Actually, IIRC, someone (the Unique??) fixed this issue on one of these PSUs before by moving the 12V rail's feedback point somewhere else... but I'll have to look through my bookmarks to see if I save this or not.

Originally Posted by RukyCon View Post
The Fans:
Don't know much about this brand, but i took both apart to clean them, and they're both ball bearing fans, so from that, they'll be good i hope.
SuperRed are pretty good fans - about the same level as Yate Loon and such... well, at least the older SuperRed fans, like in this PSU. On ATI/AMD Radeon HD video cards, they transitioned to a "sealed" design, where the fan can't be opened (easily, without some destruction.) Same with PowerLogic.
I'm not a big fan of those newer fans... pun intended.

Originally Posted by RukyCon View Post
Judging by the datecodes on this thing, i'm guessing this was made mid 2005.
Yup, you can see that even on the label where it says "0525" - made in 2005, week 25.

Originally Posted by RukyCon View Post
I did think it had something to do with being a more modern PSU, but when i saw the 5v rail was more powerful than the 12v rail, i started to think it meant something else, but i guess my initial suspicion was correct.
It's an old 5V-heavy design adapted/tweaked to work with newer PCs.
Actually, in the case of my TASK TK-930TX PSU, I eventually found out that 12V-heavy (but not too heavy, lol ) PCs work OK on it. If I try any 5V-based motherboard, the 12V rail easily goes over 12.6-12.7V, which is above 5% spec... and it also tends to swing a lot as the load on the 5V rail changes. As for the Jeantech PSU, I never tried that in a 5V-based PC. I put it in an old Athlon 64 X2 rig with GeForce 8500 GT video card, and it's been powering that rig OK with decent voltage regulation.

Originally Posted by RukyCon View Post
but maybe i gave this PSU too much credit, as i am not a expert at these things and just do these posts so fun and also to maybe learn a thing or two in the process.
Well, still give it a try at re-building, if you have the time or would enjoy doing it. Probably put some wires on the output first and see how the PSU runs with the original caps. If all is well, then recap it. This would also give you a baseline of whether the PSU was actually working or not. Otherwise you might start thinking you did something wrong with the recap and other 2nd thoughts.

Originally Posted by dmill89 View Post
Here's a PSU (a Compaq branded Hi-Pro) from an AMD K6-2 system with only a 8A 12V rail.

This is pretty heavily built for a 250W unit, hard see the markings on the silicon without disassembling it though.
Nice classic PSU there!
Those are pretty much bullet-proof with good caps.

Originally Posted by goodpsusearch View Post
We have bought ~ 15 Corsair VS power supplies (CWT platform) and none of them had its fan fail until now. Some of them failed due to dried primary caps (Aishi 400V).

I knew that Corsair/CWT put Yate Loon fans on VS series, so I was shocked to find a Chinese crap fan inside this unit:

Nobody cracked open this psu before, the warranty sticker was intact.

Lessons learnt from this story:

Brand/model matters a lot! It is not a random incident that this fan died while the Yate Loon fans on the other units keep going.
And on the sub level, it probably comes down to what kind of grease/oil these fans use.
I think the main problem is that the cheap/cheaper fans use either very little lubricant or just some low-quality stuff that gunks up / dries away quickly, leaving the bearing to run dry.

Originally Posted by goodpsusearch View Post
Please correct me if I am wrong and this is not what it looks to me: a typical crap Chinese fan
Well, TBH, I could think of many more "crappier" fans.
Te Bao Metallic Plastic / Raidmax fans come to mind here... and not only.
Globe fans are also very model-dependent - some are complete crap, others are quite OK.
And Rulian Science? Remember those from early 2000's Deer and L&C PSUs? - Those seize up very easily too.

That said, I still don't mind even the cheap "crap" bottom-of-the-barrel fans... most of the time.
Usually, they just need a good cleaning / "grooving" of the sleeve bearing and some high quality machine oil. After that, they'll work for many more years without problems.
It is a shame though, that Corsair switched brands like that mid-production.
Then again, it's Corsair - they literally put their name on stuff made by someone else, just like EVGA and many others like that. I tend not to trust such companies too much.

Now if it was a Delta-made PSU with a Delta fan, you know we are talking serious business.

Last edited by momaka; 03-11-2022 at 10:48 PM..
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