The AA1 has a built-in BIOS recovery routine, which makes it possible to flash the BIOS even if the system doesn't boot anymore. It's only meant for emergencies, that's why it's also known as crisis disk mode. Use at your own risk.

First format an USB flash drive with FAT.

Download the latest BIOS, extract all files from the zip file, put both FLASHIT.EXE and the BIOS file with FD suffix in the root directory of the drive. The files must not be in a folder. Rename the BIOS file to ZG5IA32.FD, that's important.

Turn the AA1 off, with the USB drive still connected, and make sure both battery and AC adapter are also connected.

Press Fn+Esc, keep it pressed and press the power button. Release Fn+Esc after a few seconds, the power button will be blinking. Press the power button once. The AA1 will now initiate the BIOS flash, do not interrupt it under any circumstances. After a while the power button will stop blinking, and the AA1 will reboot shortly after. Wait patiently.

The BIOS has been flashed and all settings reset to default.

If it doesn't reboot by itself, but the power button still blinks, wait a few minutes before turning it off, and try again.