Hi guys!

My computer died and I'm not sure what should I do now. I don't really know that much about computers, I'm new in my city, all my friends that have solid knowledge on this are far way and trying to help me via Skype or Ventrilo, but we are all out of solutions. Sorry for my mistakes, english is not my mother tongue.

Config:
Motherboard: ASUS Crosshair IV Formula
Video: AMD ATI FirePro V4800
Hard drive: Western Digital Caviar Green 640GB 64MB Cache SATA
Memory: Kingston 4 GB DDR3
CPU: i really don't remember but it's not bad
Power supply: Thermaltake Tr2 tx 750
Case: Thermaltake Element G

About a month ago the cpu fan started to sound forced. I opened the case, cleaned the dust as good as I could without touching too much, checked for obstacles but I didn't found nothing. I was told that it was normal that this generic fans would go bad and that I would have to change it soon. One day, (i live in Rome and it is summer, so it was a specially hot day, even with air conditioning), about a week ago, my computer just turned off. I wasn't doing anything special, working in Illustrator (I had just finished a lol game though). I turned it on again, and after one minute or so, it turned off again. All the lights in the motherboard where on, (leds and stuff), but nothing happened. At some point I recall moving the case and then the lights went off too, and it wouldn't turn off (had to power down the power supply).

I though that the heat might have been too much and didn't turn it on until next day, but with the same results. I opened it, and it had a red light in the motherboard that said CPU (according to the Crosshair manual, it is the cpu that is giving problem). But since it could turn on and load windows, even open a program (all that you could do under one minute), I figured I could be some heating problem, and I took apart the fan, cleaned it (it had a rug of dust, which explains the forced sound), cleaned the plates with clean dry cloth, applied thermal paste. When I tried to turn it on again, the motherboard turned on the lights of start and reset, but they fainted inmediately. Nothing ever came out of it again. I cleaned everything of dust, even the fan of the video card. I also checked the memories but the computer would turn on just the same, and turn off eventually. I tried turning it on without video card and nothing. The hard drive is ok because i tested it in another computer. There are no damaged or burned components in the motherboard. The power source didn't smell burnt ever, or make a sound or anything. Just silence.

I checked my power supply with an old machine and it didn't work. I bought a cheap one to test my computer, and same result: lights on the motherboard turned on briefly and then fainted. No sound, nothing.

Can someone help me? I'm up to anything that could save my beloved motherboard!!!

Thanks!
Vanessa