This prompt indicates that there is a wiring problem between the hotbed control board and the motherboard, which may be caused by poor wiring of the board or damage to the hotbed board.
Check the wiring: Make sure that the wiring of the hot bed circuit board is stable, and re-plug it if necessary to confirm good contact.
Replace the hot bed circuit board: If the wiring is normal but the problem persists, you may need to replace the hot bed circuit board.
Check the cables to the hot bed control circuit board to ensure that they are securely connected.
If the cable is loose, reinsert it to ensure that it is properly connected.
If the problem is still unresolved, consider replacing the hotbed circuit board.