I'm not a fan of dumping any old PSU into an Apple Power Supply Can without airflow/cooling analysis. Heck, I'm not sure Apple did all that wonderful a job of specifying what went in their own cans from the get go. I just took a look at the
PPT-125B Datasheet:
Seems like it calls for 18CFM of active cooling in something more like the open spaces of a piece of stereo equipment. Methinks it's not intended to be haphazardly stuffed into a metal crate with holes on top and bottom for half-assed convection cooling that's aided by just a small fan mounted above and at the back that's expected to cool not just PSU, but CRT, A/B, logic board and all the crap whith which we're packing the SE/30 to the gills.
Could someone post pics of the insides of the real deal? I'm hoping the heat sinks are pretty much aligned vertically to pull air from bottom to top inside the OEM PSU. They were set up in a vertical orientation on the 128-Plus A/B to direct airflow up and out the top vents Jobs didn't think were needed. :
Take a look at the horizontal positioning of the Mean Well PSU in the illustration. The heat sinks are three sided sheds with slots/holes in the roof for convection cooling. Turn that assembly on its side to fit within the SE/30 sheet metal as Artmix did and the passive cooling designed into the Mean Well PSU is negated.
I like the idea of putting an actively cooled, temperature controlled fan equipped Mini-ITX PSU in its stock sheet metal into Apple's can. Position air dams directing all the air entering from the bottom of the stock can so that it passes into the PSU in all the right places from the correct directions and then it all exits via the PSU's temperature controlled fan and out the upper side of the air dam setup, exiting the perforations on top, preferably aimed a bit at the system exhaust fan above and behind.
Tired, hope this makes some sense in words.
edit: when I posted I noticed the mass of connectors/wires blocking up the open side of the front heatsink shed. NOT the spot to do wire mismanagement with a zip-tie.