FANUC A20B-2902-0390 Drive Circuit Main Board

The FANUC A20B-2902-0390 Drive Circuit Main Board is a drive control PCB used in CNC servo and spindle drive systems for motion control and power regulation. It’s commonly installed in FANUC Alpha i series spindle drives (PSM-15 to PSM-37) powering CNC machining centers, lathes, and automated production equipment, and is used by maintenance teams, OEMs, and system integrators for drive repair, replacement, and CNC system restoration. Functionally, this board handles spindle and servo drive control within CNC drive and motion control systems and is mounted as an integrated part of the drive unit. It supports 15 kW to 37 kW spindle systems and is designed for compatibility with Alpha i Power Supply Modules PSM-15 to PSM-37. Classified as a Drive Circuit Main Board / PCB assembly, it’s built as an industrial-grade PCB for high-reliability operation in tough manufacturing environments. Note that this part is discontinued by the manufacturer, with support typically available through surplus or repair channels. Common replacements include Fanuc A20B-2902-0550, A20B-2902-0374, and A20B-2902-0420.