Troubleshooting "Base 64K RAM Failure"?

When I built my PC out-of-case, everything ran well except there was no display on the monitor, and the speaker continually gives a series of 3 beeps. I looked the beep code up, and it says my problem is a "Base 64K Ram Failure." I tried using my 2 sticks of Crucial RAM on every slot, by themselves, and with each other. Still three beeps. Any ideas? Could it be a mobo problem? Thanks!

Does it beep with no sticks in?

Have you defintely connected all the required power connections to the Mobo?

Take one stick and pop it in the slot closest to the CPU, does that work?

Tried the one-stick method, but I'll check the power connections. It does beep 3x with no sticks in, does that mean it's a mobo problem? Some people have suggested I reset the CMOS. Is that a good idea?