It's most likely that your ROM BIOS startup program are corrupted. If you can test the CPU and RAM on another machine to verify that it works.
It looks like your powersupply is doing OK, your floppy drive won't initiate any "seek" noise until POST have check and compare your hardware devices and IRQ, I/O and DMA are assigned. Then the floppy disk "seek" noise usually comes when it's first in the boot order. The BIOS will look for the OS first in the floppy hence the "seek" noise, then it'll either go to CD or Harddrive.
What to expect if you don't get any POST beep, is the Motherboard, then the CPU then the RAM.
If the motherboard try clearing the BIOS, if that doesn't work you'll need to find a way to flash the CMOS configuration.
CPU problem: replace it.
Ram problem: replace it.
One more thing, make sure you unplug any unecessary hardware and just leave the barebone (CPU,RAM and vide card) You'll need your keyboard also (so BIOS will initiate error if a keyboard isn't present. I would also check the floppy drive and the cable, replace each one and try flashing the CMOS again.