Based on contributions by Matthijsdek.
The most frequent controller errors students run into with a FANUC robot, and how to clear them.
What you need
- A FANUC robot with teach pendant access to the menu/system settings
Steps
Error: SRVO-003 Deadman switch released / SRVO-002 (Location) E-stop
The most common errors: the deadman switch was released (or pressed too hard) or an emergency stop was triggered. The robot stops abruptly, which can be undesirable since the stop is forceful and can stress the mechanics. If it isn’t strictly necessary, prefer bringing the robot to a stop another way (e.g. a controlled program stop) rather than triggering this. To clear the error, press RESET.
Error: MOTN-(number) In singularity
This means the robot has reached a wrist singularity (axes 4 and 6 aligning). See How to avoid and recover from singularity errors on a 6-axis robot for a full explanation of what a singularity is, how to avoid it, and how to recover from it.
Error: SRVO-230 Chain (0 or 1) ((+24V) or (-24V)) abnormal
A less frequent error, typically caused by the deadman switch not being properly engaged. To resolve it:
- Open the MENU.
- Select 0 Next.
- Choose 6 System.
- Press F1 (Type).
- Go to 6 Config.
- Scroll up until you find “Reset CHAIN FAILURE detection” and set it to FALSE.
Related
- How to avoid and recover from singularity errors on a 6-axis robot
- FANUC teach pendant buttons: quick reference
Rewritten and consolidated (Sept 2026) from the original student how-to’s: Common Errors with the Fanuc Robot.