The FANUC A20B-1008-0086 is a power board used in Alpha i Series αiPS75HV power supply modules. It forms part of the high-voltage power stage in selected 400VAC-class regenerative supplies that provide the common DC link for FANUC servo and spindle amplifiers.

FANUC tables associate this board with A06B-6120-H075 and A06B-6150-H075. It operates with a separate A20B-2003-0420 driver PCB and a model-dependent control PCB. Match the complete board label and host-module number before replacement.

A20B-1008-0086 Product Information

αiPS75HV Power-Stage Function

A20B-1008-0086 carries high-current power distribution within the αiPS75HV and interfaces with the three-phase input, converter, regenerative section and high-voltage DC bus. The complete supply returns regenerative energy toward the incoming supply while supporting connected 400V-class amplifiers.

Driver and Control PCB Matching

This board is not the separate A20B-2003-0420 driver PCB. A06B-6120-H075 uses A20B-2100-0391, with A20B-2100-0761 documented as an older control-PCB specification; A06B-6150-H075 uses A20B-2100-0390. Confirm the complete module, unit specification, PCB revision, connectors and installed power components.

Testing and Installation Notes

REACO CNC checks the label, connectors, terminals, power components, solder joints and applicable electrical functions. Alarms may also originate from the control PCB, driver PCB, IGBT modules, incoming supply, reactor, fuses, fans or connected amplifiers. Qualified personnel must isolate power and allow the high-voltage DC bus to discharge before service.

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