Multivac 80925.020 is a controller unit used in industrial automation systems, typically interfacing with motor drives and operator consoles such as the TM440013 desk terminal. Common failure modes for this class of controllers include power supply degradation (brown‑out or voltage spikes), firmware corruption leading to boot failures, and damaged I/O circuitry from overcurrent or electrostatic discharge. Begin troubleshooting by verifying the 24 V/48 V DC input rail with a multimeter, inspecting all connectors for corrosion or loose pins, and checking for error codes or watchdog resets on the diagnostic display; if available, run a self‑test routine to isolate failed modules.[oss-gpt-20b]