Nilfisk‑Advance 56397126 is the central control board for industrial cleaning equipment, handling motor drive, sensor monitoring and inter‑module communication. Common failure points on this type of board include burned or tripped MOSFETs in the motor driver section, damaged I/O protection diodes, and cracked solder joints on high‑current traces; firmware corruption can also trigger lock‑up or error codes. For first‑check diagnostics, verify that the supply rails (±12 V, 24 V) are within spec with a multimeter, inspect all connectors for loose pins or corrosion, and read any diagnostic LEDs or serial log output for fault codes before proceeding to component testing or replacement.[oss-gpt-20b]