>>atn. Expert builders<< no screen optput (there's more)

I've put together these components
P35 Gigabyte Mobo
q6600 CPU
8800GT
2GB DDR2 800 corsair
FDD
500GB SATA HDD
16X ATA DVD
650W PSU


I had it all together and I could read the BIOS. Everything looked good so I started installing XP when I had a disaster. As the HDD was formatting (and taking ages) I left the room and a power cable unraveled, touched the cpu fan stopping it and the processor got cooked. $200 down the drain! Gutted

So after recovering, I bought another q6600 and have just reinstalled it. I took out the mobo to reinstall the new one but am sure I've put it back in the same way.

Now when I boot I get a long beep, the LEDs on the RAM are flashing, I here the FDD chatter, the DVD blinks but no output is going to the monitor (monitor displays 'no input signal).

What do you think the long beep would suggest? After cooking the CPU is it likely that something else was damaged? I can't keep throwing money at this so would appreciate any expert advice on how to proceed without simply replacing everything.

Edit:
So after listening again the long beep may be a long then a short. New mobo time??