|6 blinks from the caps lock key means a BIOS authentication error. |
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BIOS authentication failure
The BIOS authentication error (Blink code 6) is extremely rare. It is the result of a discrepancy between the BIOS and the hardware that is installed on the computer. This error occurs when the BIOS cannot authenticate signatures from the hardware on the system. The purpose of the BIOS authentication is to be sure that no one has tampered with the BIOS on the computer.
If a BIOS authentication failure occurs, the computer automatically performs a BIOS recovery. If the computer does not automatically recover the BIOS, manually perform a BIOS recovery.
To manually perform a BIOS recovery, press all four arrow keys at the same time to cause the BIOS to go to the EFI partition to find and recover the current BIOS.