The FANUC A20B-2003-0430 is an IGBT gate-drive printed circuit board used inside selected high-power FANUC Alpha i power supply and spindle amplifier modules. It transfers switching commands from the main driver section to individual power semiconductor devices.

FANUC spare-parts tables identify A20B-2003-0430 as a Gate PCB and show multiple boards in applicable large modules. A common revision is A20B-2003-0430/01A. Match the complete PCB number, revision and host configuration before replacement.

A20B-2003-0430 Product Information

IGBT Gate-Drive Function

The gate PCB carries control pulses between the driver circuitry and an IGBT switching device in the power stage. Correct gate timing is essential for converter or inverter operation. A defective board may contribute to power-stage, overcurrent or IGBT-related alarms, but the associated IGBT and driver PCB must also be checked.

Module and Quantity Matching

A20B-2003-0430 is not a complete power board or amplifier control PCB. Some large modules use six gate PCBs, and neighboring ratings may use A20B-2003-0431 instead. Confirm the A06B module number, voltage class, power board, driver PCB, IGBT type, quantity, connector orientation and PCB revision.

Testing and Installation Notes

REACO CNC checks the label, connectors, gate components, solder joints and applicable signal functions. Replacing only one gate PCB without testing the related IGBT can lead to repeated failure. Qualified personnel must isolate power, verify DC-bus discharge and follow electrostatic precautions before installation.

Related resources: FANUC circuit boards, FANUC amplifier modules and FANUC CNC repair services.