1 PC Used Fanuc A20B-2101-0040 PCB Board In Good Condition A20B21010040 A2OB-21O1-OO4O

FANUC A20B-2101-0040 | Alpha i SVM1 Drive PCB — A06B-6117 Series / 6-Port / Ribbon-Style Side Connection

Part Number: A20B-2101-0040

Manufacturer: FANUC Corporation (Japan)

Product Type: Servo Drive PCB — Alpha i SVM1

Series: A20B-2101 

SVM1 Drive Board for the A06B-6117 Amplifier Generation

The A20B-2101-0040 is the drive PCB for FANUC's A06B-6117 series Alpha i SVM (Servo Valve Module) single-axis servo amplifiers. Inside an Alpha i SVM1 amplifier, the drive board is the circuit layer that sits between the control card above and the power stage below — it carries the gate drive signals to the power transistors that switch current to the servo motor, and handles current feedback measurement from the motor phases back into the servo control loop.

The A06B-6117 generation represents a later Alpha i SVM design compared to the A06B-6114 and A06B-6096 series. Each generation uses specific drive board variants — the A20B-2101-0040 is matched to the A06B-6117's physical format and electrical interface. Using a drive board from a different amplifier generation produces mismatched signal timing, incorrect gate drive levels, or physical connection incompatibility.

The 6-port configuration describes the board's interface connector count — the A20B-2101-0040 carries six signal/power interface points accessed by its ribbon-style, side-mounted connectors. This side-mounting approach places the ribbon cable connections along the board's edge rather than on the top face, allowing them to be reached within the amplifier assembly without fully removing the board from its housing.

Key Specifications

Drive Board vs Control Board — Two Separate PCBs in One Amplifier

The Alpha i SVM amplifier houses two main boards: a control card (which receives CNC commands over FSSB and manages the servo control algorithm) and the drive board — the A20B-2101-0040 — which translates the control card's current commands into the gate signals that switch the IGBT power transistors. A fault on the control card typically produces communication or feedback alarm codes. A fault on the drive board produces power-stage faults — overcurrent, IPM fault, phase fault, or transistor alarm codes — because the drive board is directly in the switching path of motor current.

Distinguishing between a control card fault and a drive board fault from the alarm code is the essential diagnostic step before ordering the replacement board.

FAQ

Q1: How does a drive board fault on the A20B-2101-0040 differ from a control card fault?

Drive board failures manifest as power-stage alarms — overcurrent (alarm 6), IPM fault, DC bus fault, or motor current phase alarms — because the drive board is in the direct path of motor phase current. Control card faults produce FSSB communication alarms or servo initialisation failures. An amplifier that fails under motor load with power-stage alarms, but shows no issue at idle, typically has a drive board fault rather than a control card failure.

Q2: Can the A20B-2101-0040 be used with A06B-6114 or A06B-6096 amplifiers?

No. Each Alpha i SVM generation uses a specific drive board matched to its physical format and gate drive circuitry. The A20B-2101-0040 is designed for the A06B-6117 series. Earlier generations (A06B-6114 uses A20B-2100-0xxx boards; A06B-6096 uses earlier A20B-21xx variants) have different connector layouts and signal levels. Substituting across generations creates mismatched interfaces. Confirm the amplifier's own label before specifying the replacement board.

Q3: Can the A20B-2101-0040 be tested outside the complete SVM1 amplifier module?

Functional testing of a drive board requires the complete amplifier module running under motor load — the gate drive signals require the power stage's DC bus and the motor current feedback, which cannot be replicated without the full assembly. Swap testing with a confirmed-good A20B-2101-0040 in the complete module is the standard diagnostic and verification approach.

Q4: What does the 6-port designation mean on this board?

The 6-port count identifies the number of signal and power interface connectors on the A20B-2101-0040 through which it connects to the power stage, control card, and ancillary circuits within the SVM1 amplifier. The ribbon-style side-mounted connection format means these connectors run along the board edge, accessible from the side of the assembly, which simplifies the disassembly procedure when replacing only this board within an otherwise intact amplifier housing.

Q5: Where is the A20B-2101-0040 sourced?

Through the FANUC Alpha i servo drive aftermarket — FANUC A06B-6117 amplifier specialists, CNC drive repair centres, and tested surplus suppliers. Many suppliers offer the board as part of a complete tested A06B-6117 SVM1 unit rather than as a bare board, because standalone board testing without the full amplifier is not conclusive. Confirm A20B-2101-0040 from the installed board's own label inside the amplifier before ordering.