Faulty RAM would not cause this. You would get the breaking glass sound if it detected it in POST, or random behaviour in the OS if it didn't, but it would at least get some distance into booting.

The machine will not start at all without a CPU card, because the CPU has to execute instructions from the machine's ROM.

Frankly, I think you have a bad video card based on your previous testing. It makes sense you would get no display from the internal video with no VRAM installed. The Voodoo would be my next move.

While recapping wouldn't be a bad prophylactic here, I don't think the caps are the problem in this particular instance.