Description:

The Fanuc A20B-3900-0074 is a memory PCB board (DIMM-style module) used in Fanuc CNC control systems, primarily within 16i, 18i, 20i, and 21i series controllers. It provides onboard memory storage for system data, parameters, and control programs, enabling stable CNC operation. Commonly installed on the main control board, it is used by maintenance teams and system integrators for system repair, memory replacement, and restoration of legacy CNC equipment.

Applications:

This Fanuc memory PCB board is used in CNC and industrial automation systems requiring reliable data storage and system memory functionality. Typical applications include CNC machining centers, lathes, milling machines, and automated production systems where controller memory integrity and data retention are critical to system performance and uptime.

Technical Specifications:

• Manufacturer Part Number (MPN): A20B-3900-0074
• Product Type: Memory PCB Board / DIMM Memory Module
• Brand: Fanuc
• Series Compatibility: Fanuc 16i / 18i / 20i / 21i CNC controllers
• Memory Capacity: 4 MB
• Memory Type: SRAM / Flash ROM (model variation)
• Form Factor: DIMM-style plug-in module
• Function: Stores CNC parameters, programs, and system data
• Installation: Plugs into CNC master/control board
• Operating Temperature: 0°C to 40°C
• Humidity: Up to 80% (non-condensing)
• Mounting Type: Internal PCB slot (controller board)
• Weight: ~0.03 kg
• Status: Discontinued / legacy component

Common Replacements:

• Fanuc A20B-3900-0074/01A
• Fanuc A20B-3900-007A
• Exact OEM A20B-3900-0074 replacement module