For AMI bios models (P55, and H55) the POST code 78;

For AWARD bios models (X58, 790, 780, 750, 730, 680, and older NVIDIA chipset boards with the post code indicators) the POST code 52;

BOTH these post code indicate that an USB device is locking up the system.


If you are getting Either POST code 78 or post code 52 please try the following:

- disconnect all USB devices from the motherboard

- remove any USB controller cards (while the computer is unplugged)

- verify that the LCD or monitor cable is firmly plugged in.

After trying the above, please test the machine again. If it is a USB or video device that is causing the issue you should get a POST code of 7F, and a failure to detect a keyboard. If this is the case plug in one device and power up. If you get the POST code 78 or 52 again, it could be that device. Test All USB devices in this manner. Most of the time this error occurs it is related to a deffective USB keyboard.

If you still get the 78 or 52 with all USB devices unplugged please try the following:

Please first try to discharge the bios completely. To do so, Please first unplug the power cord from the power supply. Next, please remove the CMOS Battery, it should be located on the bottom right quarter of the motherboard. It looks like a watch battery. Once you have removed the CMOS Battery please let it sit for at least 10 minutes so that it completely discharges the charge from the motherboard.

If you continue to get these post codes please contact EVGA Support