I took out everything day before yesterday and cleaned it, everything, properly, no haste!
I plugged in everything. I Cleaned up and placed everything on the table and turned all the plugs on the extension on.
Everything started up (The System Fan, GFX Fan, HDD & Power LEDs, Optical Drive, PSU Fan) except the CPU Fan. So there's NO BEEP, NO CPU FAN and NO DISPLAY.
When I power off the system, the CPU Fan jerks and stops again.
I have NO Idea what to do :S I cannot loose this rig right now as I have some projects to complete.
I've already halfway through got the stuff for my Core i5 rig, but right now I have no extra money to get the rest of the stuff.
As suggested, try re-seating the CPU while checking that none of the socket's pins are broken or misaligned. Also, strip the system down so only essentials are connected - CPU, 1 stick of RAM, and the video card. Leave everything else disconnected and see if it will POST.
As for the CPU fan, check it's connection to the CPU Fan header on the motherboard and make sure there are no bent pins. You could also use another fan header to power it. Try the other 4-pin header by the bottom PCI slot. If it won't reach that one, use the 3-pin one above the memory slots. If it still won't spin, give it a little tap with your fingers to see if it's just stuck.
@zipzoomflyhigh : Yeah, I plugged in both correctly. I will go home now (At office), and check out the heat sink paste. As of last night, my mobo is on my Mobo pack and bare! Only the PSU was connected and the CPU Heatsink + Fan!
While not necessarily crucial to whether or not the system will run, the broken pins can have an impact on how well the HS/Fan makes contact with the CPU. This can then have a further impact on the HS/Fan's cooling effectiveness.
So, just to get things straight, you've got it setup open-air with the CPU, 1 stick of RAM, and the GPU installed, yet it won't POST...
Did you inspect the CPU socket's pins to make sure none were broken or bent? Try the memory in the remaining slots, or use another DIMM until you've tried all 4 DIMMs in all 4 slots. Meanwhile, check the GPU and DIMM bus connectors and the motherboard slots for dirt/debris. Maybe after opening it all up and cleaning it, something got stuck on/in them. If you've got it, blast each slot with canned air thoroughly.
To clean the bus connectors of the GPU and DIMMs, you can use a pencil eraser. Gently rub it along the gold contacts, making sure to do this away from the motherboard so no bits of eraser fall into it. You could also use high-grade isopropyl alcohol (80% or higher) and a lint-free cloth (or coffee filter) to clean the bus connectors on the graphics card and DIMMs themselves.