Quadra 950 PSU options

astron

New Tinkerer
Nov 20, 2024
4
1
3
Hey, I'm lining up some wintertime projects so the Quadra 950 is on the docket...

While I'd rather do a whole-hog PSU swap but it seems like the one board someone made never got fully finished. Maybe there's a decent DIY ATX guide out there I haven't seen?

If nobody has a more elegant/modern solution, does anyone have a Quadra 950 capacitor BoM handy I can upload to Mouser? Thanks!
 

jmacz

Tinkerer
Mar 21, 2025
54
44
18
Hey, I'm lining up some wintertime projects so the Quadra 950 is on the docket...

While I'd rather do a whole-hog PSU swap but it seems like the one board someone made never got fully finished. Maybe there's a decent DIY ATX guide out there I haven't seen?

If nobody has a more elegant/modern solution, does anyone have a Quadra 950 capacitor BoM handy I can upload to Mouser? Thanks!

I just replaced my dead 950 psu with a Corsair HX1200 PSU (puts out enough amps on the 5V rail .. 30A). Fit into the stock psu casing.. just need to put together a wiring harness for the logic board side, do the usual inverter via transistor trick for ps on, wire up new 4 pin molex connectors, redo the fan wiring, and harvest the relay from the old psu to get the passthrough power port to behave the same as stock. Was pretty straight forward. I have pictures on my 68k conquests thread.

https://68kmla.org/bb/index.php?threads/jmacz-journey.45000/post-571862
 
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astron

New Tinkerer
Nov 20, 2024
4
1
3
I just replaced my dead 950 psu with a Corsair HX1200 PSU (puts out enough amps on the 5V rail .. 30A). Fit into the stock psu casing.. just need to put together a wiring harness for the logic board side, do the usual inverter via transistor trick for ps on, wire up new 4 pin molex connectors, redo the fan wiring, and harvest the relay from the old psu to get the passthrough power port to behave the same as stock. Was pretty straight forward. I have pictures on my 68k conquests thread.

https://68kmla.org/bb/index.php?threads/jmacz-journey.45000/post-571862
Thanks! Is there a clear guide out there about how to make the transistor portion of this? I think I can understand how to make the adapter given pinout, but not the other necessary part.
 

jmacz

Tinkerer
Mar 21, 2025
54
44
18
The following post was what I have been using to do this for my Mac II, IIci, Quadra 700, and now Quadra 950. The article is about the IIci but it’s the same approach on the 950 to invert the signal for the ATX.