Re: Akasa 400W atx 12v - magic smoke escape

Well, I pulled the FET and following a basic test it looks to be shorted across all pins, which would have put the full voltage from the source pin into the drive circuit on the gate pin, explaining why the SM resistor in that line looks to have been overheated. That the resistor that was limiting the driver chip's power current is blown suggests that the chip has fried and shorted, followed by the main resistor in the FET's source circuit blowing before things got really toasty...

Though I can see a way forward to repair...

Re: Akasa 400W atx 12v - magic smoke escape

Thanks Behemot
I'll have a go at checking the MOSFET and other items as you suggest. The datasheet for the PWM chip shows an example circuit that matches the PSU layout, so I just need to work some math to come up with a value for R97. R95 does indeed feed the MOSFET, a ST branded P3NK90ZFP. While checking this, I've noted another casualty, R96, from the junction of R95 to the MOSFET gate, which looks to feed into a resistor network tied up with pin 3, current sense, of the PWM device. I'll check this section also and feedback what...

Hi all, and apologies for any faux pas I make in this thread.

I've an Akasa branded PSU (AK-P040FG7, 400W ATX 12v with PFC) I'd like to revive, but it's currently deader than a dead thing.

Was installed in an old system I was given, about 2006 vintage, which had been stored in a stable for a while (without horse). On switch on, video display was showing digital noise, and then was interesting spark from rear of PSU and system shut down. Usual checks proved PSU had died (trial with replacement PSU showed that the system was ok). There was a lot of dust on the video...

Re: New Members - please post your introductions here

Been lurking for a while, and now need to ask a question or two.
Have recapped a monitor or two, one motherboard (one pending), a gpu, and revived a PSU without frying myself
Aside from tinkering with out of date tech, I take photos, read books, ride horseback, fix anything... oh yes, and I drink tea