Computer won't POST after Overclock attempt

Hello, got a little problem here. I just got a decent graphics card and in attempt to narrow the performance gap between the card and the processor, I attempted to overclock the CPU. Now my BIOS is AMIBIOS, i believe. There is only one overclock feature in this BIOS that I could find and that was to Enable Overclock Feature then raise the Mhz, which was defaulted at 200Mhz for my CPU. I raised this in 5 Mhz instances up to 220 Mhz, all the while rebottoing and loading Vista to make sure it would boot stablely.

While monitoring the temperature of the CPU in BIOS, I noticed it only went up a few degrees Celsius from 40 - 42 since the initial attempt, so this emboldened me to push higher and decide to jump 10 Mhz in the next attempt, but since noticing it maxed out at 232 Mhz, I decided to go the whole way from 220 to 232. Upon doing so and rebooting, the computer wouldn't POST and seem to be making a high pitched whine, so I immediately powered down, unplugged all cables, then reset the CMOS via jumper. After hooking everything back up and powering up, the same...No POST screen.

So, off come all plugs, open case and remove CMOS battery for between 10 -15 minutes. Still nothing. Upon power on, the DVD ROM will access, so I tried inserting the Vista DVD and nothing. The monitor doesn't power up, so obviously it's not even initializing the graphics. The keyboard doesn't respond either, which leans me towards it not being a graphics card error. I don't see how the processor could have been damaged, as I didn't raise the voltage. I am at a complete loss here. Anyone have any ideas or have had similiar happen to them? No burning component smell either, btw, which is typical of fried components.

Relevant PC Specs are as follows:
ECS K8M890M-M Motherboard Rev 1.0
Athlon 64 X2 4200+ Processor
4 GB Transcend DDR2 800 Memory
eVGA 9800 GTX+ 512MB Graphics Card

If anyone needs any more info, just reply and I'll do my best to get it to you, Thanks.