Custom built motherboard problems

I have 2 potentially dead mobo's but want to figure out why they're dead, and if usable. the problem with both is that they get power when I turn on the power (fans start, known good power supply, known good processor, known good RAM, meaning they all work in a different system). on both boards, they are socket 462, and trying to run a duron 1600. i get no signal on the monitor, but when I put all components in a known good mobo, it runs fine. one mobo is an a7v-vm and the other is an a7nbx-e, both by asus. the a7nbx-e has no onboard video, the other has onboard video, and the 3rd (known good) is a7n266-vm/aa from an old hp. what i'm thinking is that the RAM i'm using is too new for it, but cant find a spec sheet on it to determine if its a faster speed than usable on the boards (information on sticker sm564328574n03rich and spr2001121950401) any help or suggestions would be helpful. have checked everything else i know to check, but no solutions yet.

I think all of those motherboards use DDR. PC133 shouldn't fit. Make sure notches in the RAM match the ridges in the RAM slot.