FANUC A20B-2003-0280 is a three-slot backplane printed circuit board used in compatible standalone FANUC i-Series Model B CNC configurations. It provides the physical card positions and internal interconnection path required to assemble the control hardware within the CNC rack.

FANUC documentation identifies A20B-2003-0280 as the 3-slot backpanel for selected Series 16i, 18i and 21i Model B systems. It should not be confused with A20B-2003-0270, which is the related one-slot backpanel.

A20B-2003-0280 Product Information

Three-Slot CNC Hardware Interconnection

The A20B-2003-0280 forms the connection base for compatible control boards installed in the three-slot CNC frame. Depending on the original machine configuration, the assembly may contain a main control board together with I/O or option hardware. The backplane itself is not a CPU, memory module, I/O processor or servo amplifier.

A20B-2003-0280 vs. A20B-2003-0270

A20B-2003-0280 has three slots, while A20B-2003-0270 has one slot. The two boards are therefore different rack configurations and should not be selected only because their part numbers and electrical purpose are similar.

Compatibility and Replacement Checks

Confirm the complete A20B-2003-0280 number, three-slot frame, CNC series, master PCB and installed option boards before ordering. Inspect the original unit for bent contacts, damaged connectors or cabinet contamination. Replacement should be performed with power isolated and appropriate anti-static protection.

Related resources: FANUC PCB boards, FANUC CNC controls and FANUC CNC repair services.