How to Replace the Fan on LCD-Mounted FANUC CNCs

LCD-mount CNC Fan Replacement
Applicable CNCs: 3xi-B, 0i-F
Semi-applicable: Older i-series CNCs


The CNC controller is a powerful electronic unit that creates heat. Mounted to the top of the unit are cooling fans to mitigate that heat.

Each fan gives off a rotational speed signal that the CNc uses to determine if they are turning too slowly or are stopped.

Newer model CNCs have diagnostic 1002 and 1003 to report the speed of the fan.

When a fan&#‌039؛s speed is low, a flashing message of F