Why is Corsair TX 650M not powering ATX MOBO???

who makes this board?
is this a custom build or off the shelf system?

it's a dell studio 540

And we turned the Psu on by the rocker switch at the back of the PSU, did we check ?.
Its a very easy mistake to make, or forget about the rocker on the back of the Psu in its off mode.   Oh shucks I must remember to check that.

no i didn't make any mistakes as far as hook up, the PSU will power the Mobo, just won't POST

Does the Corsair tx650m CP-9020039 work in another system?

well unfortunately i took it back because i was pissed and I've been disassembling and reassembling my PC and testing for 3 days now. i should have tried it in my old (i mean win 95 old) desktop if it would have been compatible. I'm thinking the OEM dell configuration may be a bit to sensitive for that power supply even though the Corsair is supposedly backwards compatible with ATX 2.01. My other theory is that the load of the bare Mobo, CPU, and ram wasn't enough to power the PSU. possibly the wattage was to high and the ratio of current to voltage wasn't enough to flick the PSU on switch. yet the weird thing is the CPU fan spun and wouldn't stop. I've been researching mobo load and measuring current through the mobo all day so now that i have a whole host of new information that doesn't seem to be helpful in this case i think i'll go back to the trial and error route. even tho it has me baffled I'm going to pick up the Tx 550m model tomorrow. i'm not the only person to have this issue with this mobo and this exactly PSU so hopefully the lower wattage will play nice with my mobo and i can avoid selling it and buliding from scratch