A20 error

Issue

Cause

Solution

1. Make sure 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, the motherboardmay have a bad controller and will need to be replaced.