A20B-8100-0135 Fanuc 18i Model A Mainboard

Buy online your A20B-8100-0135 Fanuc 18i Model A Mainboard reference A20B-8100-0135 from our e-store Cnc-shopping, specialist in CNC machine-tools spare parts.

This FANUC master board is an OEM CNC control spare part used in the Fanuc 18i series Model A platform. It serves as a core control electronics board for the LCD/MDI operator panel assembly, making it a common solution when you need a reliable replacement unit to restore a Fanuc 18i-based machine with display and operator interface faults linked to the main board.

The A20B-8100-0135 is designed for Fanuc 18i Model A systems without PC function. In the field, this detail matters because the hardware and boot structure differ from versions equipped with a PC option. Matching the exact board reference helps avoid startup issues, display communication problems, and parameter retention faults that maintenance teams typically see after an incorrect board swap.

On many machine tools and industrial installations, this master board is fitted directly on the LCD/MDI unit in the operator panel. It supports the operator interface side of the control, so a failed board can show up as a dead screen, unstable MDI behavior, or a control that does not complete a normal power-up sequence even though the rest of the CNC cabinet is energized.

This part is commonly encountered on Fanuc 18i-TA and Fanuc 18i-MA configurations using the Model A hardware family. For retrofit and maintenance sourcing, the safest approach is always to confirm the board ID on the existing assembly and cross-check the CNC series and Model A designation before ordering a spare.

Reference: A20B-8100-0135

Manufacturer: FANUC

Product type: Fanuc 18i / 180i CNC Series master board (mainboard)

Main function: Main control board for the Fanuc 18i Model A LCD/MDI operator panel assembly, used to restore CNC operation by replacing a defective motherboard / mainboard

Applications: CNC machine tools and industrial equipment fitted with a Fanuc 18i series Model A control, especially installations using an integrated LCD/MDI unit on the operator panel (behind the Fanuc yellow backplane)

Key technical data: Model family Fanuc 18i series Model A, version without PC function, used as an 18i A master board for 18i-TA and 18i-MA type systems, manufactured in Japan. Suitable for maintenance replacement when the original board is defective or damaged and the machine requires a like-for-like board reference.

In a maintenance shop, the A20B-8100-0135 is typically purchased as a CNC replacement component to get a stopped machine back online after an operator panel or mainboard failure. Keeping a tested spare board for common 18i installations is a practical way to cut downtime, especially on older machines where original electronics can be harder to source and lead times are unpredictable.

For rebuilders and CNC service teams supporting legacy Fanuc controls, this Fanuc 18i Main board is also used for planned repairs on machines that must stay in service. A correct reference match helps preserve system consistency across the operator panel assembly and reduces the risk of compatibility problems during field replacement.

Each unit is supplied as a tested unit checked on appropriate CNC test benches or simulators by skilled engineers, focusing on correct power-up behavior and stable operation relevant to this control family. The board is packed for industrial transport and supplied with a warranty to support professional maintenance and repair work. Fast dispatch is available depending on inventory, with worldwide shipping options for MRO and OEM support teams.

As the Fanuc 18i Model A generation ages, the A20B-8100-0135 is frequently sourced as an obsolete part or emergency spare to avoid extended production stoppages. Cnc-shopping supports long-term machine life through spare-part sourcing, and depending on the case, repair service or exchange service options may be available for compatible Fanuc electronics.

Frequently asked questions about A20B-8100-0135:

Where is this board typically installed on a Fanuc 18i system?
It is commonly fitted on the LCD/MDI unit within the Fanuc Yellow backplane operator panel assembly on machines equipped with a Fanuc 18i series Model A control. This is why failures often present first as operator interface and display related issues.

Is A20B-8100-0135 intended for 18i Model A controls with a PC function?
No, this board is specified for Fanuc 18i Model A without PC function. For correct replacement, match the exact CNC model and the existing board reference from the machine.

What should maintenance teams pay attention to during replacement regarding CNC data?
Before changing a motherboard or related CPU/boot elements, it is standard practice to back up SRAM data (Trhough PCMCIA Card or Etherne dataserver, depending of your existing configuration, you can follow the Replacement procedure from the Fanuc 18i Maintenance manual which will explain it step by step how to replace this Fanuc mainboard) and restore it after replacement. This helps keep machine-specific parameters and programs consistent with the original configuration.