I'm trying this again. I worked on it for about 3 weeks in December, then got side-tracked with the holidays and repairing my father-in-law's and brother-in-law's PCs (both required new mobos, what a pain!). Ok, so I'm back to tackling mine. I've got all new parts for the build except a used CPU & Ram I bought from a friend, both worked when he removed them.
I'm starting with just the basics to try to get it to boot up (once it boots, I'll install the video card, HDD, CD/DVD burner, but I want it to boot first).

I have:

PSU: Coolmax VL-600B Power Supply - 600-Watt, PCIe <new>

Mobo: ASUS M3A78-CM AM2+/AM2 AMD 780V Micro ATX AMD Motherboard <new>

CPU: AMD Phenom 9950 Agena 2.6GHz Socket AM2+ 125W Quad-Core Black Edition <used>

RAM: OCZ SLI-Ready 2GB (2 x 1GB) 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400) OCZ2N800SR2GK <used>

I have this setup outside of the case and plugged into my KVM switch (so I know the video, keyboard, and mouse work (I'm typing on them).
When I turn it on, the PSU fan spins, the cpu fan spins, the green light on the mobo comes on, and after awhile the cpu, northbridge, and southbridge are warm (not hot).
But I get no beeps or video signal at all.

I tried swtiching and removing the Ram, but still no beeps.
I also tried installing a PCI-e and a PCI video card. Still nothing.
I also reset the CMOS and changed the battery.
I already replaced the mobo once (I guess it is possible I got 2 bad mobo's, but not likely).
Is there any way to confirm a dead mobo or cpu? (I'm not having a good mobo year, so maybe that is it)