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

[Behemot]

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

If you mean ViPER, it's used for +5 V SB only, no? How can it also drive the whole primary?

As I later edited my previous post, there is one coil with small ceramic/tantal cap on primary, maybe some self-resonant circuitry? Unfortunatelly, I cannot have a look, I am at home and I left the PSU in the company owning this magazine office, thought I won't need it for anything anymore

[ben7]

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

If you mean ViPER, it's used for +5 V SB only, no? How can it also drive the whole primary?

As I later edited my previous post, there is one coil with small ceramic/tantal cap on primary, maybe some self-resonant circuitry? Unfortunatelly, I cannot have a look, I am at home and I left the PSU in the company owning this magazine office, thought I won't need it for anything anymore

No, I was talking about the bigger chip on the secondary. And yes, the VIPer can't power the whole PSU... It's probably a simple push-pull circuit design.

[Behemot]

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

If you mean the PS222S, it's a "3-Channel Secondary Monitoring IC With Over-Current Protection And an Additional 12V OCP Channel". Not a PWM of any kind.

I haven't noticed center-tapped transformer, but to be honest, I am not 100 % sure

[Th3_uN1Qu3]

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

The Viper could be used for the main PSU, having the standby run a classic 2-transistor design... But somehow i think you're missing something.

ben7, an optoisolator cannot drive a switching transistor directly. There's always a PWM controller, or a driver transistor after the opto.

[Behemot]

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

Well, there is only the A928A, which seems to be KSA928A PNP transistor. You have the same pictures as I do, do you see anything else in there which may run the primary besides VIPer or some kind of self-oscilator?

[Pentium4]

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

This is the worst power supply I have ever seen. Classic Leadman piece of shit! Funny thing is, I have another Xtreme Gear PSU that is actually decent too...Those Jay'Long input caps are bulged. I don't know why they even bothered putting a 4A bridge on it. I don't really need to explain how bad this thing is, it speaks for itself I mean....there's only 3 filtering caps and one is for the damn -12V rail!!! Are you kidding? The ripple is probably reaching 1V around 150W Decent coil but it isn't wound very tight. Size 28 transformer....Surprised to see JPCE-TUL caps in this, the rest are Cheng and TNC. The Fan just says "FAN" on it What do you guys think, one of the worst ever?

[Behemot]

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

Well, I kinda like that cable output layout. Besides that, good for parts The rectifier is nice, heatsinsk does not eem to be that bad as well.

What about the other silicon? Transistors, rectifiers?

[c_hegge]

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

Wait a minute, There's no cap on the 12V rail?! 1V+ of ripple wouldn't surprise me at all. What a complete pile of junk! I'd be sledgehammering that after blowing it up on the load tester.

[ben7]

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

^ yeah, whats up with companies not using capacitors on all voltage rails!?

They must figure the motherboard capacitors will be enough :yawn:
Even if they are enough, the radiated EMI from the power cables would cause hell!

[Pentium4]

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

This thing doesn't deserve any words of praise the heatsinks are super flimsy though. And that green tall cap is for 12V, it says 2200uF but i'm sure it's lower. The other cap is for 5V. There is a 30A schottky for the 5V, and a fast recovery 20A for 3.3V and 10A for 12V

[tom66]

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

One on eevblog I saw.
http://www.eevblog.com/forum/reviews...got-something/

Spot the missing major components...
How long will it last without them?

[lti]

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

And that green tall cap is for 12V, it says 2200uF but i'm sure it's lower. The other cap is for 5V. There is a 30A schottky for the 5V, and a fast recovery 20A for 3.3V and 10A for 12V

The 3.3V rail is the one without any filtering? Did that come out of a computer?

One on eevblog I saw.
http://www.eevblog.com/forum/reviews...got-something/

Spot the missing major components...
How long will it last without them?

They made it so efficient that it doesn't need heatsinks.

[c_hegge]

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

I thought the 3.3V rail on that Leadman used DC-DC as there is no coil, but a 20A fast recovery rectifier? Super group regulated with no capacitors! I'd hate to think of all the RAM those things must fry.

[lti]

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

I posted a nearly identical power supply in another thread that had no +12V filtering.

[Pentium4]

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

I bought it from a bundle of power supplies I hope it wasn't powering a computer for very long!!! This Coolmax came with it too, it looks to not be too bad after having some work done do it. Replace the Input caps, add a 4A rectifier, an X cap, recap it and replace the fan. Primaries are Seacon, the rest are Ricon, Sapcon, and Asia X

[c_hegge]

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

That Coolmax is a Sun Pro.

[Pentium4]

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

Explains the horrible cap choice. They've made much worse though

[PeteS in CA]

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

Those heatsinks ... Where's the beef?! IMO, 200-225W! Somehow it seems appropriate that "con" is part of the name of all those caps ... and not because of the archaic name for a capacitor, "condenser". Those blue Y caps look a bit thin. Are they safety agency approved?

[momaka]

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

What do you guys think, one of the worst ever?

Hardly.
They have cut many many corners in that PSU indeed, but the overall PCB design is not too bad - at least they still left space on the secondary to add more caps and PI coils. The PSUs that don't have space for those are instantly added to my "never put in a computer" list. Also, it's a forward converter design - technically a bit more efficient that half-bridge.
But in it's current state, I wouldn't even use it to power LEDs.

Those blue Y caps look a bit thin. Are they safety agency approved?

I'd be surprised if they are.

[Pentium4]

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

So efficiency in the mid 70's? I'm not sure if I want to even try improving this thing, but I guess it would be good for 200W safely with a few parts thrown in there. The Coolmax is dead, not even 5VSB, I'm not sure what its issue is yet. And no the blue Y caps are not safety approved!