Allen-Bradley · PowerFlex 4M Adjustable Frequency
A critical hardware failure has been detected within the drive's control board and/or its integrated input/output (I/O) section. This means the drive cannot reliably process control signals or manage its I/O, rendering it inoperable and potentially affecting interconnected control systems.
Click steps to track your progress.
Disconnect all external wiring from the drive's I/O terminals (e.g., DI1-DI6, AI1-AI2, AO1, DO1-DO2).
Power cycle the drive and observe if the F122 fault clears without any external I/O connected.
With I/O disconnected, measure resistance between each I/O terminal and the drive's control ground to check for internal shorts.
Visually inspect the I/O board for signs of damage such as burn marks, swollen capacitors, or discolored components.
If the fault persists with all I/O disconnected, prepare to replace the drive's control board or the entire drive unit.