If you think your BIOS is corrupt, first try resetting the it's configuration to the factory default settings, as that may resolve your issue. If you can't POST, disconnect both the power adapter and the battery from the laptop, and then remove/disconnect the internal coin cell battery (page 27 in the service manual). Leave the coin cell battery disconnected for at least 2 minutes to clear existing the BIOS settings, then reinstall/reconnect it and reassemble the laptop. If the laptop is able to POST, you should get a message stating that the BIOS configuration is invalid and that the default values will be loaded. If the laptop fails to boot (load the OS), you either have to reconfigure your drive settings in the BIOS, or there's an issue with the boot drive.
Normally, if the BIOS hasn't been updated or manually configured, there shouldn't be any corruption. If the computer previously worked fine and one day it wouldn't boot, it could be something else, like a failed or corrupt storage drive, or system board component.
