Fanuc Pcb Board A20B-3900-0131 A20B39000131 A2OB-39OO-O131

FANUC A20B-3900-0131 DRAM Memory Module

Overview

The A20B-3900-0131 is a FANUC memory module in the A20B-3900 series.

Public industrial listings consistently identify this model as an 8 MEG DRAM MODULE, which places it in the storage and memory side of the control hardware rather than in the CPU, I/O, or amplifier-board category.

In practical service work, a memory module is selected by exact memory type and exact part number because the installed control depends on the original memory structure already used in the system.

Matching the same module helps preserve the existing storage profile inside the control hardware and keeps the board-family continuity unchanged.

Technical Data

Application Value

This module is suited to installed FANUC control systems that already use the A20B-3900 memory-board family and require the same 8 MB DRAM configuration.

It is especially relevant in control repair, refurbishment, and board-level memory replacement where the original hardware setup must stay aligned with the installed memory structure.

Because memory modules are defined by their exact storage function, this part should be matched by exact model rather than by general visual similarity.

Public listings present it specifically as a DRAM module, which makes that identity the most important selection point.

Selection Notes

The key checks are the exact part number, the A20B-3900 family, and the published identification of the module as an 8 MEG DRAM MODULE.

Those are the main compatibility points supported by the public references for this model.

FAQ

Q1: What kind of module is A20B-3900-0131?
It is a FANUC DRAM memory module. Public parts sources consistently identify it as an 8 MEG DRAM MODULE, which means it belongs to the memory section of the control hardware rather than to the CPU, spindle, or I/O section.

Q2: Why is the 8 MB DRAM description important?
Because that description is the core identity of the module. A memory board is selected by its storage type and capacity, and public listings for this model consistently use 8 MEG DRAM MODULE as the defining description.

In replacement work, that exact match is essential.

Q3: Is this a main PCB or a memory-only board?
The public descriptions place it in the memory-module class. It is not listed as a main PCB or a power board.

Its role is tied to the control’s memory structure, and that is the function that should remain unchanged when replacing it.

Q4: What kind of replacement work is this module used for?
It is typically used in board-level maintenance and memory-module replacement for FANUC controls already built around this exact storage profile.

Public listings present it as a dedicated memory spare rather than as a general board-level accessory.

Q5: What should be checked before ordering?
Check the installed part number, confirm the machine requires A20B-3900-0131, and verify that the original memory board is the same 8 MB DRAM type in the installed hardware.

Those are the main compatibility points for this model.