In which situations is BIOS programming required?

The BIOS/UEFI is the firmware that recognises the hardware and starts the operating system when the device powers on. When it becomes corrupted, the device may not start at all. In that case the BIOS chip is read with a programmer and the correct firmware is written; a backup of the existing BIOS is taken first and the right version for the device is verified.

When is it needed?

• Interrupted update: If the power failed or the device shut down during an update, the BIOS can be corrupted.
• Device that won't start: If the fans spin and stop, there is no picture and the hardware measures fine, the BIOS is suspect.
• Wrong version: If a BIOS file not meant for the device was installed.
• After a motherboard repair: Some repairs require the BIOS chip to be replaced or rewritten.

How is it programmed?

1. The hardware is measured first to confirm the problem really is the BIOS; power and short-circuit faults are ruled out.
2. The BIOS chip is read with a programmer and a backup of its contents is taken.
3. Firmware matching the device model and board revision is identified; device-specific data such as the serial number is preserved.
4. The correct firmware is written, verified by reading it back, and the device goes through a start-up test.

What to keep in mind at home

Only update the BIOS with the file for your device from the manufacturer's website; keep the adapter connected and don't switch the device off during the process. If an update was interrupted, ask a service rather than switching the device on and off repeatedly. See BIOS programming. If the device turns on but shows no picture, read this article; if it doesn't respond at all, see short circuit detection.