My computer will start up then shut down and start up again after about 2 seconds and it stays on but there is no display from either my GFX card or my integrated graphics, my motherboard's led light indicating there is a problem with the cpu is on. The reason I think the problem is my motherboard is because this happened after I took out all my components and cleaned the case, and I didn't even touch the CPU.
Check all of your power connections to insure that none are loose, then check to see that your RAM, graphics card and other components are firmly seated. Also check to see that nothing is shorting any components to the case.
Did you reattach the ATX12V power connector and graphics power connector?
You can also try clearing your CMOS (bios) by unglugging and also moving the CMOS pins from 1-2 to 2-3.
It really sounds like something is not seated properly.