• Updated 2023-07-12: Hello, Guest! Welcome back, and be sure to check out this follow-up post about our outage a week or so ago.

IIsi PSU on it last legs - what are my best choices for a modern replacement?

3lectr1cPPC

Well-known member
Well my luck with my IIsi's PSU didn't last long. Had it on playing some games and it suddenly shut off. Now it does start if I disconnect the hard drive, but emanates a concerning high pitched noise, and it seems the 12v rail may be a bit low or weak. It's been recapped, so that shouldn't be a factor here, my guess is that she's done and had it. And yeah I tried a different HDD, it's just too weak now.

What are my current options for ridding myself of it? I know there's now a mac ATX adapter of sorts out, but I saw Mac84 try it on stream and it didn't end up working on his IIsi, so it looks like that may not be an option?

Thanks.
 

sarnau

Member
Recap – especially the 2 SMD caps – should fix it, if it is not too far gone. It is worth a try.

Otherwise I've build a bunch for many different Macs of ATX adapters. The Gerber files, etc. I found on Github. It is always good to have some ATX adapters around, just for testing.
 

joshc

Well-known member
I guess the two of you missed that OP said it's already been re-capped.

There are smaller ATX PSUs which should work the chassis, or perhaps there's a compatible MeanWell unit that will fit. It's really just a case of researching PSUs and finding one that will physically fit. There are two ways you can go about the conversion, either shoving an entire complete ATX-style PSU housing in there, or taking apart an ATX PSU and relocating the PCB and wiring harness over to make it fit. I've done both methods. The latter is more tedious and involved.
 
Top