My FIC KA-6100 mobo has both AT and ATX power connectors. Since AT and ATX power supplies have the same for factor, I decided to upgrade my AT case with and ATX power supply. I tried to use an AT reset switch on the ATX power button jumper on my mobo, but it won't POST (it will POST with a cheap baby ATX power supply I borrowed to test). Is an ATX power button anything more sophisticated than a simple contact switch (doesn't seeem like it on my multitester)? Do I now need to find a cheap ATX case? I'm hoping ATX voltages will let the GF2 Ti I bought last year work in my old mobo.

The ATX power and reset buttons should be momentary contact switches. Do not use a regular switch that stays on all the time.

Simple answer to this is, use the RESET switch as the POWER switch. It is a momentary switch. And go without the RESET switch. I mean, if you REALLY need to do a soft reboot, there is always Alt Ctrl Del! Or the power switch! (I have done this before!)

"Simple answer to this is, use the RESET switch as the POWER switch." That's my point, I DID use the reset as Power-On (I also have a second Reset from another ATX case). The external of the 2 fans in the power supply runs at slow speed, the IDE CDR drive light flashes, but no POST. I bought a PowMax/Leadman 500w (not the most expensive brand, perhaps this is my problem). It did work with a cheap Baby-ATX. I RMA'ed the PowMax when it didn't work, but the new shrink wrapped power supply failed the same way. I guess I'll have to borrow a different brand from a friend to test.