Need Some Computer Help

Ok, recently there was a thunder storm that has left my computer showing me only a black screen. All four of the fans including the one in the PSU turns on flawlessly and the lights on the motherboard are on, but the computer does not make any kind of beeping sound like it normally does on start up(bios not posting). I've had symptoms like this before and a change in power supply worked in the past. I plugged in an old power supply which didn't work at all(not even one fan came on) so I'm pretty sure that one is in fact dead. I then pulled out the CMOS battery and cleaned both video cards(for dust) and placed the CMOS battery back in in order to reset the BIOS. After doing all this I turned it on once again, but this time however there was an extremely loud continuous beep that was emitted. I checked the display next to the battery for the "POST" code, it showed the letter "F", not FF, just F. I have no clue what this means as just one F isn't even in the manual for codes that it can show. I should also mention that the computer doesn't turn off no matter how long I hold the button down, and I don't know if this could be a function of burnt ram.

I'm guessing resetting the BIOS caused it to emit the beeps, probably what it should of been doing all along(way of telling me whats wrong). The beeping makes me rethink that its not the power supply but rather RAM issues. I would greatly appreciate any feedback that is given, as I'm really confused right now as to what it could be.




Custom
Motherboard: nforce 780i sli
Video card: 8800gt x 2(SLI)
Power Supply: 700W OCZ
PCU: Intel Quad Core
Ram: [Total 4gb] 4x1gb ddr2 800
OS: Windows XP