Infinity 500 W PSU Review at Funkykit (Goes Blammo)

[bobnova]

Hi all, my second Cheap PSU Review is up at Funkykit now.
It's an Infinity 500 W unit, it actually came quite close to being reasonable. The combination of no UVP on the 12V rail and a fan control thermistor attached incorrectly resulted in grievous overheating, switching transistor death (both), and blammo.
There's a video link at the bottom of the second autopsy page.

Infinity 500W PSU Review

I have another cheap unit coming for next month I believe.

[McSteel]

Too bad about the thermistor... Having something more substantial than the ever-overused 13007s on the primary meant this could've actually survived. Also the ripple and v-sag are most definitely a consequence of overheating...

As for ChengX, chuck them in the Asia'X/BH/12KJ/etc pile (of manure).

Thanks for the review!

[bobnova]

It really is. In theory those transistors will do something like twice the current the 13007s will.

I've yet to run into 12KJ, the rest of those are familiar. Based on the units I've found 'em all in I have a nasty suspicion that the ChengX are rather worse than Asia'X (impressive, really) but possibly marginally better than BH.
That's only going off a few units though. I wouldn't want any of 'em on a daily basis.

[c_hegge]

FYI, those jumper wires on the 12V output aren't OCP shunts. That's where the PI filter coils should have gone. Having the 12V rail drop so far would have further crippled the fan. Even if the fan controller wanted to spin the fan up, it couldn't with only 9V. It also looks like the ripple did go through the roof when it warmed up, going by that last table on page 2.

EDIT: Looks like we both came to the same conclusion on the two Infinity units (3/10)

[bobnova]

I think with the fan operating correctly the switches would have been happy and the voltage would have stayed up, it took a good 15m to droop from 12v to 11.5v, all told it was 30m before it went bang. Definitely not OCP shunts, didn't intend to imply that, not sure why I called 'em shunts actually. Oh well.

I'm tempted to spend the six bucks to get a couple new transistors and to move the fan thermistor just to see what happens. That'd take actual money and effort though.

[c_hegge]

You could well be right. The thermistor on my one was properly attached, and it was able to hold 100% load without killing the switchers.

[Testakraze]

thx for the review

[c_hegge]

I attempted to fix my Infinity 450W by using an L-shaped piece of copper. One side was screwed onto the primary heatsink, while the other side went over the DM311. It held up a little longer but the problem still occurred, even with the fan wired directly to 12V. I ended up just ditching the PSU, although I re-used the fan (a blue LED 140mm) as a case fan in my brother's PC. He loves it.

[bobnova]

It is a snazzy fan. I peeled it out of the dead unit, building a fan controller for it now. Hopefully mine works better than Infinity's did.