Used FANUC board A16B-3200-0325 A16B32000325 A16B-32OO-O325

FANUC A16B-3200-0325 | Series 18i-A / 180i-A Standalone Main CPU PCB — 18i-MA / 18i-TA / 180i-MA / 180i-TA

The Backplane of an 18i-A Standalone Control

The A16B-3200-0325 is the main CPU PCB for FANUC's Series 18i-A and 180i-A CNC controllers in the standalone configuration. In a standalone control, the CNC electronics are housed in a separate cabinet from the operator panel. This main PCB is the backplane of that control enclosure — the board onto which CPU processor cards, FSSB servo communication modules, graphics cards, FROM/SRAM memory modules, and option boards are mounted. When this board fails, the entire control fails with it.

The 18i/180i Model A was FANUC's mid-to-high performance i-Series CNC platform, deployed across machining centres, turning centres, and compound machine tools from the 1990s and 2000s. Many of these machines remain in active production. The 180i-A variant adds Open CNC functionality — a Windows-based PC environment running alongside the CNC kernel — for custom operator interfaces and data management applications. Both 18i-A and 180i-A use the A16B-3200-0325 as their main board; the differences between them are in software and installed PC hardware, not in this PCB.

The standalone architecture accommodates more plug-in slots than FANUC's LCD-mounted designs, making it the configuration used for higher-option-loading applications.

Key Specifications

Critical: Model A Is Not Model B

The A16B-3200-0325 is the Model A main board. The later Model B main board uses a different part number (A16B-3200-0421 and related). Model A and Model B plug-in boards are not interchangeable — connector definitions and board form factors differ between the two generations. Confirm the model generation from the installed board's label and from the machine's documentation before ordering a replacement.

Supplied Without Plug-In Boards

The A16B-3200-0325 is the main board only. CPU processor cards, FSSB modules, graphics cards, FROM/SRAM memory, and DRAM modules are each separate components with their own part numbers. When replacing this main board, the plug-in boards from the original control can typically be transferred to the replacement provided they are undamaged. If the event that failed the main board also damaged plug-in boards, they must be sourced separately.

FAQ

Q1: All LEDs on the main board are off at power-up. Is the main board faulty?

Start with the control power supply, not the main board. The standalone enclosure contains a dedicated power supply board (5V / 24V) that feeds the main PCB. A failed power supply produces the same zero-LED symptom at a fraction of the cost of main board replacement. Verify the power supply's input and output voltages first. Only after confirming the power supply is correct and LEDs remain off should the main board be considered faulty.

Q2: The control reaches the FANUC boot screen but stalls and will not proceed to normal operation.

Boot screen stall on 18i-A systems is most commonly a FROM or SRAM module issue — corrupted FROM content, unreadable FROM module, or invalid SRAM parameters. Access the boot menu and check the FROM module status. Attempt a FROM verification from the boot screen. If FROM check fails, the FROM module needs attention before normal operation can resume — this is a plug-in board issue, not a main board issue.

Q3: Can plug-in boards from an 18i-B (Model B) system be used in the A16B-3200-0325?

No. Model A and Model B plug-in boards are not interchangeable. Connector definitions, board form factors, and software versions differ between model generations. Only use Model A compatible plug-in boards with the A16B-3200-0325. Identify compatible boards from the machine's original parts list or from the labels on the currently installed boards.

Q4: After replacing the main board, do parameters transfer automatically from the plug-in boards?

If the SRAM module is intact and transferred to the replacement main board, its stored parameters are available after the swap — provided the backup battery maintained data through the power-off period during repair. Always verify the SRAM battery condition and confirm all parameters are correct and complete before returning the machine to production.

Q5: The machine is an 18i-MA. Does the A16B-3200-0325 also suit the 18i-TA and 180i variants?

Yes. The A16B-3200-0325 is the main board for the full Series 18i-A / 180i-A platform: 18i-MA, 18i-TA, 180i-MA, 180i-TA, and other sub-variants in the Model A generation. The differences between machining centre (MA) and turning centre (TA) sub-types are in software configuration and parameters, not in the main board hardware itself.