FANUC A20B-8101-0430 power supply board A20B81010430 A2OB-8IOI-O43O

A20B-8101-0430 | FANUC A20B-8101 Series Power Supply PCB — 043x Range / CNC and Drive Power Board

A20B-8101 — FANUC's CNC and Servo Amplifier Board Series

The A20B-8101 series is a confirmed FANUC PCB family spanning main CPU boards and servo amplifier power boards across multiple CNC and robot system configurations. Examples confirmed in this session and from the broader A20B-8101 product range:

The A20B-8101-0430 as a "POWER SUPPLY PCB" sits within the A20B-8101 series at the 043x position — confirmed alongside servo amplifier power boards within the same series, consistent with a power electronics or power supply function.

Key Product Information

Power Supply PCBs in FANUC Servo and CNC Systems

Power supply PCBs in FANUC CNC and servo systems serve defined and critical functions within the power electronics architecture:

DC bus regulation: Maintaining the correct DC bus voltage that servo drive inverters use to produce motor current — monitoring, protecting, and controlling the rectified DC supply.

Auxiliary voltage generation: Generating the regulated low-voltage supplies (±15V, 5V, 24V) that power the control electronics, encoder interfaces, and signal processing circuits on other boards within the drive or CNC unit.

Protection and monitoring: Detecting overvoltage, undervoltage, and overcurrent conditions on the power supply rails — triggering protective shutdowns before damage propagates to connected electronics.

Application Scenarios

Power supply PCB fault — servo or CNC system: A FANUC CNC or servo system develops power supply level faults — incorrect supply voltages, power supply alarms, or erratic behaviour across multiple boards that all trace to a common supply rail. The A20B-8101-0430 power supply PCB is identified as the fault. Replacement restores correct power distribution.

Servo amplifier power board maintenance: A FANUC servo amplifier in a robot or CNC machine tool system undergoes power electronics maintenance. The A20B-8101-0430 is the power supply PCB within the specific amplifier being serviced.

FAQ

Q1: How do I confirm A20B-8101-0430 is the correct power supply PCB for my FANUC system?

Read the part number from the installed board's label. If it reads A20B-8101-0430, this is the confirmed replacement. Cross-reference with the applicable FANUC maintenance manual's board layout to confirm the board's position and function in the specific CNC or servo system.

Q2: What symptoms indicate an A20B-8101-0430 power supply PCB fault?

Power supply PCB faults typically cause: incorrect supply voltages that affect multiple boards simultaneously, power supply alarms on the CNC or drive display, erratic system behaviour that cannot be traced to a single functional board, or complete failure to establish correct operating voltages during power-up. These symptoms affect the whole system rather than a single axis or function.

Q3: Are there safety precautions specific to handling a power supply PCB like A20B-8101-0430?

Power supply PCBs are directly associated with high-voltage power circuits. Before accessing: switch off and lock out the mains supply, verify the DC bus has fully discharged using a calibrated voltmeter, and verify all auxiliary supply rails are de-energised. Handle A20B-8101-0430 with an anti-static wrist strap on an ESD-safe surface — the board contains both high-voltage power components and low-voltage signal electronics.

Q4: Does replacing A20B-8101-0430 require system reconfiguration?

Power supply PCBs typically contain no user-configurable parameter storage. After fitting the replacement A20B-8101-0430, the system's control electronics re-establish operation from the corrected power supply. Verify all supply voltages are correct before enabling the CNC or servo system. Confirm from the applicable maintenance manual whether any post-replacement checks specific to the power supply board are required.