Computer Won't Shut Down

[Screems]

Hi everyone, a few months ago I put together a computer and found out it had a bad stick of memory as well as not being able to shut down. I got rid of the memory, but the problem still persists. When I click "Shut Down" in the Windows Start menu, the computer will go through the shut down procedure, the monitor will shut off, but then the lights and fans in the computer will continue working. A red CPU_LED light on the motherboard flashes repeatedly. If I click the power on button it will turn on just fine, and the computer restarts and goes to sleep fine as well. Is this a power supply or motherboard problem?

Specs:
Windows 7 64-bit
i5 2500k
GTX 560Ti
ASUS P8Z68-V GEN3
Seasonic S12II 620W
1TB Seagate HDD
4GB RAM (had 8 but as I said, one stick was bad)

 

[daswilhelm]

maybe check the power settings in BIOS? possibly try loading the defaults and see if that changes anything.

not to familiar with that power supply but could be related.

 

[popatim]

What are the lights and the fans plugged into?

 

[Screems]

2 of them are connected into the motherboard, and the other 2 are connected into the power supply.

Should I try to unplug the ones that are connected to the PSU?

Also, the BIOS settings are at default, tried flashing the BIOS as well.