FANUCA20B-3300-008516 MB DRAM Memory Module – Plug-In CPU Daughter Board for i-Series CNC and Robot Controls

Product Description

What this part is

This is a FANUC A20B-3300-0085 16 MB DRAM module — a compact plug-in memory daughter card that seats on the main CPU printed circuit board inside a FANUC i-series CNC or FANUC robot control rack. It supplies the processor’s volatile working DRAM. The battery-backed SRAM and FROM that hold part programs, parameters and ladder live elsewhere on the control, so this card carries working memory only.

Decoding the order code

A20B: FANUC’s prefix for printed circuit boards and plug-in board assemblies. A86L- is FANUC’s bought-in component prefix.

-3300: the board family this memory card belongs to, the i-series / robot CPU board group.

-0085: the specific card, the 16 MB DRAM capacity variant. Its siblings -0084 and -0086 are the same physical card at other DRAM capacities, so the last four digits are the capacity field.

/03B: the edition or revision suffix stamped on the board, as in A20B-3300-0085/03B. Editions are usually backward compatible within a capacity.

Specifications

Brand: FANUC

Manufacturer: FANUC

Part Number: A20B-3300-0085

Base Number: A20B-3300

Memory Capacity: 16 MB DRAM

Edition Suffix: /03B

Series: FANUC A20B-3300 CPU board group (i-series CNC / robot control)

Mounting Type: Plug-in daughter card, mounts on CPU main board via standoffs

Controller Platform: FANUC i-series CNC and FANUC robot control (R-J3 generation racks)

Country of Origin: Japan

Manufacturer Status: Legacy, supported by FANUC repair-exchange

Item Weight: 5.0 oz

Condition: New – Open box, new takeout, tested

Fault behaviour

DRAM faults on a Fanuc control present as intermittent system alarms, watchdog resets and boot failures rather than a clean dead machine. A spare card isolates a suspect CPU board: a fault that persists after the memory is swapped sits on the main board. The card is small and static-sensitive.

Set composition

1 Pc. One memory card, a daughter board with no standalone connector to the outside world.

Interchange

MPN variants: A20B-3300-0085, A20B33000085, A20B 3300 0085, A20B-3300-0085/03B, A20B3300-0085, A20B-33000085.

Fitted on FANUC i-series CNC controls and on FANUC robot controllers including the S-430i, M-6i, M-16i, M-440iH, M-770i and A-520i families.

A20B-3300-0084 and A20B-3300-0086 are the same card at other DRAM capacities and share the footprint. The capacity that matches the control’s parameters is the one to order.

The CPU main boards this card commonly sits on include A16B-3200-0330 and A17B-3300-0200.