Reference number: CH000383

A20 error.

Issue:

A20 error.

Cause:

Issue related to the keyboard and/or keyboard controller.

Solution:

1. Ensure the keyboard is connected to the proper port on the back of the computer.
2. Turn off the computer and disconnect the keyboard and verify there are no bent, burnt or broken pins on the keyboard connector or on the keyboard connector on the back of the computer.
3. Try a different keyboard on the computer.
4. Unfortunately, if all of the above recommendations do not resolve your issue, it is very likely that the motherboard may have a bad controller.