After spending lots for a PPC A4000 , the old, weary 145W original PSU seemed like a ticking bomb to me, so I decided to use a modern ATX PSU for my 4000...
First thing to do was to order the following from amigakit.com , an
ELBOX ATX-to-A4000 power converter and an
ATX Power Switch for the converter.
I wanted to use the original power on/off button the A4000 has, and I thought: Why don't I use the original PSU's case? both their switches are screw compatible, so it was just a matter of opening the old PSU, removing the stuff inside, and screw the new ATX switch. Also the MINI-ATX PSU I got had the screws on the same place as the old PSU, so I just screw it in place... I did not use the whole A4000 PSU case, only the parts needed to support a 80x80 fan and the switch... with the atx psu screwed in place it is just a matter of inserting the old case in place, you will understand it better after looking at the attached pics... and all work nice, and very easy to mod! I only need to think how to cover the space under the MINI-ATX PSU (last pic) maybe I add a small fan blowing air inside...