The AMB Electronics MBE3‑50 is a digitally controlled inverter drive for three‑phase motor applications, rated at 1 A input, 400–500 VAC, 400–800 VDC and delivering 2 A/50 V output with an active magnetic bearing system. Common failure points in this class of drives include power supply degradation (overvoltage or ripple), phase loss or imbalance on the three‑phase input, overheating of the inverter bridge, and firmware corruption that can lock the drive into a fault state. Begin diagnostics by verifying the incoming 400–500 VAC supply for correct voltage, frequency, and phase continuity; check the DC bus voltage for proper rectification and ripple levels; then review any error codes displayed on the drive’s panel or via its communication interface before proceeding to component-level inspection.[oss-gpt-20b]