Code SRVO-042: MCAL alarm(Group:%d Axis:%d)
Issue Description & Safety Warning
The Fanuc R-30i Series Robot Controller has triggered a critical MCAL alarm(Group:%d Axis:%d) alarm. Immediate attention from a qualified operator or maintenance technician is required to prevent secondary damage to the equipment or spoiled parts during the manufacturing cycle. Always ensure standard safety and LOTO procedures are followed before accessing electrical cabinets.
Official Troubleshooting Steps
Cause: This alarm means that the contacts of the magnetic contactor have stuck together. The alarm condition occurs if the magnetic contactor is already on when an attempt is made to turn it on. The alarm condition is detected between the time the contact sticking occurs, and the time an attempt is made to turn it on. Remedy: 1. Check the magnetic contactor, and replace it if necessary. 2. If the contacts of the magnetic contactor have stuck to each other, turn off the circuit breaker. If the power is switched off without turning off the circuit breaker, the servo amplifier might get damaged, because the stuck contacts keep 3-phase 200 VAC applied to the servo amplifier. 3. Replace the E-Stop unit. 4. Replace the servo amplifier.
Source: FANUC Robot R-30iA Alarm Code List Operator's Manual
Last reviewed: 2026-07-01 · Verified against the manufacturer’s official documentation.
About Fanuc R-30i Series Robot Controller Alarms
Fanuc controllers include extensive self-diagnostics that flag or halt the machine when a fault is detected. Error code SRVO-042 on the R-30i Series Robot Controller identifies one specific fault condition — its documented cause and the official corrective steps are listed above, sourced from Fanuc's service documentation. Always confirm against the manual for your exact machine configuration and follow LOTO procedures before servicing.
Complete Alarm List: 6553 Fanuc R-30i Series Robot Controller codes.
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