SRVO-001

Visually inspect E-stop button state

Examine the red EMERGENCY STOP button on the operator panel. If it appears depressed (flush or recessed into the panel), it is in the activated state. The button should protrude approximately 5-8mm above the panel surface when released.

Do not attempt to release the E-stop if an actual emergency condition exists or if personnel are in the robot work envelope.

Release the E-stop button

Grasp the E-stop button and rotate it clockwise (typically 45-90 degrees) while applying slight outward pressure. You should feel and hear a mechanical click as the button pops out and the internal contacts close. The button should remain in the extended position.

On older teach pendants with 5000+ hours of use, the E-stop mechanism may require firmer rotation due to contact wear. If excessive force is needed, plan for button replacement during next maintenance window.

Reset the alarm on teach pendant

Press and release the RESET button (typically blue or white button near the E-stop). The SRVO-001 alarm should clear from the alarm history. Verify on the teach pendant display under MENU > ALARM > F1 [TYPE] > CURRENT that no E-stop alarms remain active.

If the alarm clears but immediately reappears without touching the E-stop, proceed to wiring and contact diagnostics as this indicates an intermittent fault.

Test E-stop functionality

With servos enabled, press the E-stop button to verify it activates properly, then release and reset again. This confirms mechanical operation. The alarm should trigger instantly when pressed and clear reliably when released and reset.

Perform this test only when robot is stationary and no automatic program is running.

Verify button physical release state

Confirm the E-stop button is fully extended and rotated to the release position. Press RESET on the teach pendant. If SRVO-001 alarm does not clear despite the button being physically released, this indicates an internal contact failure.

On R-30iA controllers, check the I/O diagnostic screen: MENU > I/O > F1 [TYPE] > Digital In. Look for *CSTOPI (operator panel E-stop input). If it shows ON when button is released, the contacts are failed closed.

Check E-stop circuit continuity

Power down the controller completely (lockout/tagout). Using a multimeter set to continuity mode, disconnect the E-stop wiring at the operator panel connector and measure across the E-stop switch terminals with the button in released position. You should read <1 ohm resistance (closed circuit).

LOCKOUT/TAGOUT required. Verify zero voltage at all controller power terminals before proceeding. Consult electrical drawings for your specific controller model.

Replace E-stop button assembly

If continuity test fails with button released, replace the E-stop switch assembly. For Fanuc teach pendants, this is typically part number A05B-2490-C3xx series (model-specific). Remove the four screws securing the E-stop housing, disconnect the wire terminals noting positions, install new switch, and reconnect per wiring diagram.

Keep a spare E-stop button assembly in your maintenance inventory. These are high-cycle wear items. Replacement takes 10-15 minutes and prevents extended downtime. Torque mounting screws to 0.5-0.7 Nm to avoid cracking the housing.

Verify repair and document

After replacement, power up the controller and verify SRVO-001 alarm clears with RESET button. Cycle the new E-stop button 5-10 times to confirm reliable operation. Document the replacement in maintenance records with date and part serial number.

After E-stop replacement, perform a mastering verification check via MENU > SYSTEM > Master/Cal > F4 [MASTERING] to ensure position data was retained during the repair.

Inspect teach pendant cable and connectors

Examine the entire length of the teach pendant cable for visible damage, kinks, or wear points especially near the cable entry points. Check the connector at the teach pendant and at the controller interface panel (typically JOP connector) for bent pins, corrosion, or loose retention clips.

The teach pendant cable is a high-flex component. On robots with mobile teach pendant use, cable failures typically occur within 150mm of the connector ends due to repeated flexing. Look for outer jacket cracks or abnormal stiffness indicating internal wire breakage.

Check E-stop circuit at controller terminals

Access the controller cabinet and locate the safety circuit board (typically mounted near the operator interface connectors). Verify terminal tightness on the E-stop circuit terminals. For R-30iB controllers, check terminals EES11 and EES12 on the IOPC board. Measure voltage across these terminals with E-stop released; should show circuit continuity (typically 0V differential on closed circuit).

High voltage present in controller cabinet. Qualified personnel only. Use appropriate PPE and follow NFPA 70E guidelines. Only measure E-stop circuit terminals with controller powered on if necessary for diagnosis; otherwise use lockout/tagout procedures.