View Full Version : Is it possible to wire an (old) ATX power supply to an AT compatible Motherboard

September 13th, 2017, 12:32 PM
I stayed after school for tech club I was resented with a model of an old Pentium 1 motherboard with ram and all, I asked if we could turn it on but we have no power supply that supports the AT standard. the bottom line is can mod an ATX psu to connect to the AT connector

September 13th, 2017, 01:09 PM
The short answer is yes you can. Just google the AT and ATX pinouts and go from there. Newer ATX PSUs won't have a -5V rail, and there maybe less power on the 5V rails than you need, so I'd be weary of that. The other thing is the power on. AT power supplies have a physical switch to power them on, one that cuts off the mains voltate where as ATX power supplies us a soft on to turn them on, the green wire coming out of the PSU needs to be grounded before the thing will turn on.

All of that said your best bet would be to buy an ATX to AT wiring harness from ebay such as this one: http://www.ebay.com/itm/NEW-EPS-ATX-24-PIN-to-AT-P8-P9-CONVERTOR-WITH-5V-A-DUMMY-LOAD-MADE-IN-USA-/252708704697?hash=item3ad69cd1b9:g:JGcAAOSw-3FZDMdh

September 13th, 2017, 02:04 PM
can some one gimme a guide to do this i dont want to break anything