a few questions

Hello!

Got a few questions for ya. I recently cleaned out my PC, took it all apart and all that, put it back together, and upon turning it on, it went through POST, hit the windows loading screen, then a quick BSOD flash and it rebooted. i went into BIOS and didnt see anything off, so I saved and exited, rebooted, windows boot screen, went to safe mode, and the BSOD flashed and rebooted. the next time it hit POST, started detecting hard drives, rebooted to nothing....no POST, no alarms, no video signal, no smoke, no joy. just spinning fans.

I've been tinkering for a while now and have it narrowed down pretty well. However there are a few things I'm not 100% on.

1. Does a computer POST without RAM? I was under the impression that with bad RAM it will freeze during POST, but with no RAM you got the scary beeps. When I boot with no RAM there is no difference from when the RAM was in.

2. If you have a faulty CPU, would it still POST? I have the P6N Diamond and its got the 4 light indicator, however nothing ever lights up, so I thought it was the motherboard that was borked, however- If I remove the CPU and attempt to boot, it detects that there is no CPU and shuts off...soo....does that mean the MB is fine? (even though there are still no lights on the bracket, no beeps..just a shutdown.

I'll give my system specs in case there is anything else im not thinking of...

MB- MSI P6N Diamond
CPU-intel C2duo E6700 (OC to 3.2ghz)
RAM-mushkin pc2 8500
vid- MSI 8800gtx
PSU- PC power and cooling silencer 750w quad

It was an assembled and working setup for the last 2 months (stable OC the whole while).
Tested the PSU and all voltages are good,(plus the CPU and NB heatup so ya know SOMETHING is churning em). Tested with different known good RAM, in every slot, to no avail.
reseated everything again and again. checked all pins and nothing was bent.
Tried it in and out of the case, no shorts(that are visible..stupid tin whiskers...).
Went back to the stock cpu cooler, still nothing.
cleared CMOS via CMOS CLEAR button
Removed battery and let it sit unplugged for 20+ hours (went to bed and then to work)
Powered on with every combination you can imagine. just CPU, CPU+RAM, CPU+RAM+VGA...ect....no luck
the whole time I had the diag bracket and the system speaker plugged in and neither of them did anything.
one thing to note- it is a possibility since sometimes I go into superman mode and dont properly ground myself that I fried something, or a cat brushed up against it..or walked on it...or whatever it is cats like to do to MB while you sleep.

as I said im thinking its either the MB or the proc, and im leaning towards the MB, but before I buy a new one, I'd like to be as positive as possible and exhaust all ideas. one possibility is maybe (BIOS is a little unknown to me) there is a way to flash the bios. If it got corrupted thought the CMOS reset should have done the job, right?

OK my apologies, I'm babbling. Thanks for takin the time to read this, sorry for the ugly formatting, and thanks in advance for any help you can give me.