FANUC A20B-3300-0310 i-B Pentium CPU Module with 16MB DRAM

Overview

The A20B-3300-0310 is a CPU processing module in the A20B-3300 family. It is described as an i-B Pentium CPU module with 16 MB DRAM, and listings associate it with 16i-B, 18i-B, and 21i-B control platforms.

Service references also describe it as a plug-in module that mounts on the main master PCB, which clearly places it in the controller processing path rather than in the display, I/O, or communication-board layer.

This module is important because it contributes directly to processing performance inside the CNC.

In practical maintenance work, CPU modules are selected by exact processor and memory profile, since the installed control depends on the same plug-in processing architecture already used on the main board. 

Matching the same model helps preserve the controller’s original computing structure and memory configuration.

Technical Data

Applications

This module is suitable for installed FANUC 16i-B, 18i-B, and 21i-B controls where the original system already uses the A20B-3300-0310 plug-in CPU position.

It is especially relevant in controller repair, CPU-module replacement, and control restoration where the same processing and memory profile needs to be maintained.

Replacement Guidance

Before ordering, confirm the installed module code directly on the hardware and verify that the control family is 16i-B, 18i-B, or 21i-B. It is also important to confirm that the failed part is the plug-in CPU module and not the main board itself.

On CPU modules, exact processor family and memory configuration should remain aligned with the installed control structure.

FAQ

Q1: What kind of module is A20B-3300-0310?
It is an i-B Pentium CPU module with 16 MB DRAM. That places it in the processing layer of the control system rather than in the display, communication, or power-support sections.

Q2: Why is the 16 MB DRAM detail important?
Because CPU modules are selected not only by board code but also by their processor and memory profile.

The 16 MB DRAM specification is part of the installed computing structure of the control, so it should remain matched during replacement.

Q3: Which controls is this module commonly associated with?
Listings consistently connect it with 16i-B, 18i-B, and 21i-B control families.

That gives it a clear installed-base role in FANUC i-B generation CNC hardware.

Q4: Is this the main board?
No. It is described as a plug-in CPU module mounted onto the main master PCB. That means it is part of the controller’s processing path, but it is not the complete motherboard itself.

Q5: What should be checked before buying?
Check the installed module label, confirm the control family, verify that the failed part is A20B-3300-0310, and make sure the original module is the same i-B Pentium CPU with 16 MB DRAM type.

Those are the main compatibility points for correct replacement.