Whenever I shut down my computer, the PSU (Coolermaster GX 650w) does not cut-off power to the motherboard and everything. I think this may be what is causing lots of the other problems. My motherboard is a Z68x UD4 from gigabyte, does anyone know how to fix this? thanks
Would it be possible that the computer goes into standby? What happens if you hold down the power button for several seconds? Does the system shut down? Note that +5V standy power will always be present (indicated by a LED on the motherboard), but no other voltage should be provided by the PSU.
Is this a new build? Are you sure the motherboard isn't shorted out? If a new build, did you test the motherboard outside of the case before assembling the system? Did it shutdown properly?
If you have another PSU, then use it to determine if the PSU is faulty, but you could also test it using the procedure described at http://www.overclock.net/faqs/96712-how-jump-start-powe.... You should disconnect everything except for case fans or the DVD drive, but don't leave important components like the video card or hard disk connected.
*sigh* another reason I have to get around to returning my mobo. boo-hoo.
Keep swapping parts until something works. Or take one minute to measure voltages on six wires from PSU to motherboard. Then what is actually defective could be defined. Power supply is told to power off or on by a power controller. Is that working? Those numbers posted here would say so immediately. Then you replace what is defective. Know you are not curing symptoms. And actually learn how the computer really works. That much from only one minute of labor.
The list of suspect is more than a motherboard or PSU.