Servo Alarms: First Checks

Problem

The machine stops and the HMI or servo drive reports an alarm code on one axis. The same code may recur intermittently under load or at speed, or the alarm may have appeared after a component replacement.

Possible Causes

1. Mechanical overload or binding on the driven axis.
2. Following-error buildup from tuning or load changes.
3. Cable, connector, or encoder-signal faults.
4. Drive parameter mismatch after a component replacement.
5. Regenerative or supply conditions in the drive cabinet.

What to Check

• STEP 1Record the exact alarm code.Photograph the HMI or drive display including code, axis number and time — this is required for any support request.
• STEP 2Inspect the axis mechanically.Locked out per procedure, move the axis by hand where the manual permits, feeling for binding or debris.
• STEP 3Check cables and connectors.Inspect the axis cable run for damage, tight bends and loose connectors, especially near moving harnesses.
• STEP 4Try one controlled reset.Clear the alarm and run at reduced speed to see whether the fault is load- or speed-dependent.
• STEP 5Log the pattern.Record code, axis, speed and product for every occurrence — patterns are the fastest route to root cause.

Corrective Actions

• Do not repeatedly reset a recurring servo alarm — repeated restarts under a real mechanical fault can convert a small repair into a major one.
• Remove debris or obstructions found on the axis and re-verify at low speed.
• If the alarm appeared after a part replacement, verify drive and controller parameter sets were transferred correctly.
• Escalate with the full alarm history once the pattern is recorded.

Advanced Diagnostics: Servo Motor and Drive Replacement

When diagnostics confirm a servo motor or drive component, the replacement is a documented procedure — parameter sets and alignment decide whether the new component behaves like the old one.

• STEP 1Transfer the parameter set before removing anything.The outgoing drive's parameters must be read out and archived per the manual — a new drive without them is a re-commissioning, not a replacement.
• STEP 2Replace with the qualified component.Order via the spare parts request form with the machine model, serial number and the component's part number.
• STEP 3Load parameters and check mechanical coupling.Alignment of the coupling is part of the replacement, not an optional refinement.
• STEP 4First run at reduced speed.Verify axis motion, home position and alarm-free operation before returning to production speed.