System won't power on.

[wtf8269]

This is the second time this has happened to me. The resulting conclusion from the last time was that I had a DOA mobo. I've since RMA'd it and now have a new one. Now the same thing happens. Mobo and DRAM power LEDs are on once the PSU is switched on, but nothing happens when I press the power button.

Here's what I've done so far:
-Tested case switch with a multimeter, works.
-Tried jumping mobo with a screwdriver, nothing.
-Tried onboard power button, nothing.
-Tested each graphics card in a separate system, both work.
-Tried booting with no graphics cards, sound card, hard drives, fan controller, or dvd-rw, nothing.
-Jumpstarted the PSU on its own, works.
-Connected fan controller w/ fans to PSU, works.
-Tried either of the two 8 pin mobo connectors on my PSU, nothing.
-Tried running the system outside of the case, nothing.

Am I missing something?? I've built more PCs than I can remember and I just can't figure out what the hell is wrong. Could it really be another DOA mobo?

I have not tested the RAM or CPU in another system, but these components would only keep the system from POSTing, not prevent it from turning on completely, correct?

Thanks in advance for any replies; I'm really clueless on this one.

 

[Dangman]

Specs of your entire PC would help.

 

[wtf8269]

Sorry, it's in in my signatures on other forums.

-E8500 w/ Scythe SCORC-1000 & Zalman 120mm
-DFI LP DK X38-T2R
-8gb (4x2gb) G.Skill PC8000 5-5-5-15
-2x ASUS 3870x2s
-4x160gb RAID 0 Main, 2x 500gb media storage
-Lian Li PC-A70B (In process of being modded).
-PC Power & Cooling T12W 1200w
-Creative AudigyLS. Klipsch RF-3II fronts, Yamaha NS-A222 rears, Klipsch RC-3II center, Klipsch SUB12
-Samsung SyncMaster 204B
-Vista Ultimate x64 (Irrelevant I suppose)

 

[Dangman]

I have not tested the RAM or CPU in another system, but these components would only keep the system from POSTing, not prevent it from turning on completely, correct?

It is possible for the CPU to keep the system from not turning on if it's dead. So test the CPU in another system. While you're at it, test the RAM as well.

If both of those check out, then you have another dead mobo on your hands.