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

[Behemot]

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

Usually ppl just stick something in, for the good feeling you can scope it if it is not oscillating.

[Th3_uN1Qu3]

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

The pi filter coils have too low inductance to play a part in the feedback loop.

[Behemot]

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

They can have too high for example for -12 V, I sucesfully brought one PoS to oscillation by sticking some inductor instead of wire…changed it for resistor-size inductor than.

[PeteS in CA]

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

Yeah, with those wimpy input rectifers, heatsinks, input lytics and main transformer, 250W might be optimistic. But for 200W should be OK. Since you'll be changing them anyway, upping the input lytics to 470uF or even 680uF would be good. And if you can find some 4A or 5A axial standard recovery rectifiers that would fit, replacing those would be good. Do both changes and 250W might be credible.

[nasuga]

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

A couple of weeks ago I've had a cheap powersupply die on me. I can't remember the model but it was a codegen and it came included with codegens 4063 case and was rated for 500W. I left my computer running one night (I tend to leave it running) and when I came back it was dead. I thought maybe a capacitor had blown but I was wrong. What it looks like is that the transformer melted and burnt inside the powersupply. Nobody heard anything when the computer died. The underside of the board was black from the intense heat. I should of taken more pictures and written down the details but it was before I found out about this board and after I've thrown it out. I guess I missed the power supply with the compressor last time I cleaned . I'm glad there was a soldered fuse or else it would of taken my motherboard and possibly my videocard.

[Agent24]

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

If nothing else was burnt, then maybe that choke shorted by itself or there was some power line disturbance which blew it. Seems odd

[nasuga]

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

If nothing else was burnt, then maybe that choke shorted by itself or there was some power line disturbance which blew it. Seems odd

Agreed. My brother (who studied as an electrical engineer) told me that it's possible that the varnish or coating on the windings dried/melted and it started shorting. I don't think there was a power line disturbance because I was home at the time and I didn't notice any problems with other electronics or with the lights. Also, the power supply was plugged into a surge protector.

[c_hegge]

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

Looks like the input filtering coil. That's very unusual. I've never seen an input filtering coil burn up like that.

[goontron]

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

Looks like the input filtering coil. That's very unusual. I've never seen an input filtering coil burn up like that.

looks underrated to me....

[nasuga]

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

I replaced it with a brand new Corsair RM550. Rumor is that they used CapXon caps inside but with a flash light I was able to spot a large chemicon but I couldn't identify the rest. I'm just glad there was a fuse that protected my motherboard even though it's riddled with KT and WX caps.

[c_hegge]

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

^
The large PFC cap in those is indeed a Chemi-Con. But the rest of them will be capxon, and will probably fail within 3 years.

[Agent24]

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

I replaced it with a brand new Corsair RM550. Rumor is that they used CapXon caps inside but with a flash light I was able to spot a large chemicon but I couldn't identify the rest.

Going by this: http://www.pcper.com/reviews/Cases-a.../Detailed-Look it should have UCC KY which are good. (Can see one there anyway, not sure what is buried under the wiring though)

Wouldn't be surprised if some use\used CapXon though, I saw a Corsair CX400, it was full of Su'scon and OST, which are pretty mediocre.

[nasuga]

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

The PSU has a 5 year warranty if it fails. I figured it outweighed the fact that it was built with bad caps. Chances are though that it will fail right after the warranty expires now come to think of it.

[momaka]

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

Looks like the input filtering coil. That's very unusual.

Yes.

This is one reason I don't like to see input filtering of ANY kind BEFORE the fuse (except maybe large PPFC chokes). If your breaker doesn't trip, you could be in big trouble.

[Behemot]

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

If no breaker trips (there should be at least two of them - the main one and than special ones for phases or even outlets/ligths etc.), why are yo ucertain fuse will burn? There are always slow fuses for high currents, like 5+ A for PSU which wil never draw more than 2 A.

[ben7]

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

A possible cause for the filter coil to burn like that is, of course, a shorted turn or two.
Another is, the power supply could have gone unstable and caused excessive high frequency ripple on the primary side, which could burn out the choke (which filters out the high frequency, preventing it from going back into the mains wiring).

[Agent24]

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

Another is, the power supply could have gone unstable and caused excessive high frequency ripple on the primary side, which could burn out the choke

Interesting, haven't heard of that one before. What causes that?

[momaka]

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

^Me neither. I think the primary transistors should fail way before that happens, though. Would be an interesting experiment to try to see what it takes to cook one of those input chokes, though (besides too much current). More specifically, how much RF/noise would be needed.

[goodpsusearch]

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

^Me neither. I think the primary transistors should fail way before that happens, though. Would be an interesting experiment to try to see what it takes to cook one of those input chokes, though (besides too much current). More specifically, how much RF/noise would be needed.

http://translate.google.com/translat...l-350-W/1885/1


nice fireworks btw:
http://www.clubedohardware.com.br/ar...l-350-W/1885/8

[momaka]

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

^Very interesting. I wish they (clubedohardware) would have done a deconstruction of the coil to see why it burned... i.e. too thin of a wire, improper wire, or what exactly. Would also have been cool to bypass the PPFC and filtering and try to run the PSU again to see how far it would go. The heatsinks look decent. I bet it could hit 300W of raw power (that is, ripple probably won't be in spec on output).

So I guess the conclusion is that now we can't trust input filtering coils in cheap PSUs either.