Ok been having problems with my computer it would turn off and on and give no video, and no leds on the mobo would light up or it would not post. So i took it out of the case and started it up to find out that it works tried a few different things, put it back into my case added my other stick of ram, wireless, (have not order graphics yet) and it worked so then i added all the fans and I/O front panel stuff when it started stopped and wont not light up leds on mobo, aka back to the beginning
Asrock Extreme4 Z77
Cooler Master HAF X
Corsair 8GB Vengeance
Western Digital 500GB Blue
OCZ Vertex 4 64GB
ASUS Wireless Card
ASUS DVD drive
Sounds like it might be your case shorting the motherboard. It's going to be painful but you have to go through a process of elimination. First, your PSU, you can usually buy a voltage reader at a PC store for about $10.
Next plug in the I/O plugs in one at a time and turn on the PC every time.
Don't forget to test your HDD, Optical Drive, SSD and your fans.
It could be the plugs or it could be a pin on the mobo.
It sounds like it might be the fans or I/O since it stopped working after they were plugged in.