: The scanner attempts to find its "zero position" by reading a white strip under the glass. If the strip or glass is dirty, the motor keeps pulling the belt, causing a rattling sound and subsequent error.

: Ensure the internal ribbon cable connecting the scanner to the main board is not bent, cracked, or loose.

: Some models have a physical lock switch on the side or bottom; ensure it is in the "unlocked" position. Patched Firmware Solution