These post codes will appear if you have a problem that would prevent your system from booting up. If you have video on the screen you would generally see a error message and have options at the bottom that state "press F1 to continue, or DEL to enter setup". Here are some of the common error messages that could appear;

• CPU has been changed - This is a normal error if the board is brand new OR the processor has been replaced with a different processor.
• CMOS checksum error defaults loaded. - This will indicate that the motherboard bios has been reset by the CMOS reset switch or the BIOS has lost power.

If you do not have video and are getting these POST codes, It would most likely be that the video card in your system is not functioning.

In rare cases these POST codes with out video could be that the motherboard bios has been corrupted. Usually powering down and removing the CMOS battery, then letting it discharge for 10 minutes, may resolve these cases.

Here are the POST codes by chipset series.
If you are getting the 7F POST code on:

• any 600 chipset series motherboards
• any 700 chipset series motherboards
• any x58 chipset series motherboards

If you are getting the 85 POST code on:

• any P55 chipset series motherboards
• any H55 chipset series motherboards
• any W555 (SR2) chipset series motherboards