Fanuc series 0 alarms or known as the 900 system alarms listing faults and error codes. Followed by 300 alarms (Communication alarms) and 400 series alarms (axis and spindle alarms). These systems are commonly refered to as Fanuc Series 0-T and 0-M.

This page details the alarm code, type (name of the alarm and what is normally posted on the Series 0 display and a description of the alarm/error.

For Fanuc parts on Series 0-A, 0-B or Series 0-C, 0-D, 0-F or if you have found yourself on the wrong alarms page then go back to our Fanuc Alarm index page

SERIES 0 SYSTEM ALARMS
910
MAIN RAM PARITY
This RAM parity error is related to low-order-by-test.
911
MAIN RAM PARITY
This RAM parity error is related to the low-order bytes.
912
SHARED RAM PARITY
This RAM parity error is related to the low-order bytes of RAM shared with the digital servo circuit.
913
SHARED RAM PARITY
This parity error is related to high-order bytes of RAM shared with the digital servo cicuit.
914
SERVO RAM PARITY
This is a local RAM parity error in the digital servo circuit.
915
LADDER EDITING CASSETTE RAM PARITY
This RAM parity error is related to low order bytes of the ladder editing cassette.
916
LADDER EDITING CASSETTE RAM PARITY
This RAM parity error is related to the high order bytes of the ladder editing cassette.
920
WATCHDOG ALARM
This is a watchdog timer aalrm or a servo system alarm for axis 1 to 4.
921
SUB CPU WATCH DOG ALARM
This is a watchdog timer alarm related to the sub-CPU board or a servo system alarm for axis 5 or 6.
922
7/8 AXIS SERVO SYSYTEM ALARM
This is a servo system alarm related to axis 7 or 8.
930
CPU ERROR
Replace the master PC board.
940
PC BOARD INSTALLATION ERROR
PC board installation is incorrect. Check the specification of the PC board.
941
MEMORY PC BOARD CONNECTION ERROR
The memory PC board is not connected securely.
945
SERIAL SPINDLE COMMUNICATION ERROR
The hardware configuration is incorrect for the serial spindle, or a communication alarm occured.
946
SECOND SERIAL SPINDLE COMMUNICATION ERROR
Communication is impossible with the second serial spindle.
950
FUSE BLOWN ALARM
A fuse has blown
960
SUB CPU ERROR
This is a sub-CPU error.
998
ROM PARITY
This is a ROM parity error.
Absolute Pulse Coder (APC) or Serial Pulse Coder (SPC) Alarms
3n0
nth-axis origin return
Manual reference position is required for the nth axis.
3n1
APC alarm: nth axis communication
nth axis communication error. Failure in data transmission.
3n2
APC alarm: nth axis over time
nth axis APC overtime error.
3n3
APC alarm: nth axis framing
nth axis APC overtime error. Failure in data transmission.
3n4
APC alarm: nth axis parity
nth axis APC Paraity error. Failure in data transmission.
3n5
APC alarm: nth axis pulse error
nth axis APC pulse error alarm.
3n6
APC alarm: ntha xis battery voltage 0
nth axis APC battery voltage has decreased to a low level so that data cannot be held.
3n7
APC alarm: nth axis battery low 1
nth axis axis APC battery voltage reached a level where the battery must be renewed
3n8
APC alarm: nth axis battery low 2
nth axis axis APC battery voltage reached a level where the battery must be renewed( including when power is OFF)
3n9
SPC ALARM: n AXIS PULSE CODER
The n axis ( axis 1-8) pulse coder has a fault.
Series 0 Servo Alarms
400
SERVO ALARM: 1, 2TH AXIS OVERLOAD
1-axis, 2-axis overload signal is on.
401
SERVO ALARM: 1, 2TH AXIS VRDY OFF
1-axis, 2-axis servo amplifier READY signal (DRDY) went off.
402
SERVO ALARM: 3, 4TH AXIS OVERLOAD
3 axis, 4 axis overload signal is on.
403
SERVO ALARM: 3, 4TH AXIS VRDY OFF
3-axis, 4 axis servo amplifier READY signal (DRDY) went off.
404
SERVO ALARM: n-TH AXIS VRDY ON
Even though the n-th axis ( axis 1-8) READY signal ( DRDY) is still on. Or, when the power was turned on, DRDY went on even though MCON was off.
405
SERVO ALARM: ZERO POINT RETURN FAULT
Position control system fault.
406
SERVO ALARM: 7, 8TH AXIS OVERLOAD
7TH, 8TH AXIS VRDY OFF
7-axis, 8-axis overload signal is on.
4n0
SERVO ALARM: n-TH AXIS -EXCESS ERROR
The position deviation value when the n-th  axis stops is larger than the set value.
4n1
SERVO ALARM: n-AXIS-EXCESS ERROR
The position deviation value when the n-th axis stops is larger than the set value.
4n3
SERVO ALARM: n-th AXIS -LSI OVERFLOW
The contents of the error register for the n-th axis exceeded power.
4n4
SERVO ALARM: n-TH AXIS DETECTION RELATED ERROR
N-th axis digital servo system fault.
4n5
SERVO AALRM: n-TH AXIS- EXCESS SHIFT
A speed higher than 4000000 units/s was attempted to be set in the n-th axis.
4n6
SERVO ALARM: n-TH AXIS -DISCONNECTION
Position detection system fault in the n-th axis pulse coder ( disconnecton alarm).
4n7
SERVO ALARM: n-TH AXIS-PARAMETER INCORRECT
This alarm occurs when the n-th axis is in one of the conditions below:
The value set in Parameter no 8n20 (motor form) is out of the specified limit.
 A proper value ( 111 or -111) is not set in parameter no 8n22.( motor revolution direction).
Illegal data ( a value below 0, etc) was set in parameter No 8n23 ( number of speed feedback pulses per motor revolution)
Illegal data ( a value below 0, etc) was set in parameter No 8n24 ( number of speed feedback pulses per motor revolution)
Parameters No. 8n84 and No. 8n85 (flexible field gear rate) have not been set.
An axis selection parameter ( from No.269 to 274 is incorrect.
An overflow occured during parameter computation.
490
SERVO ALARM: 5TH AXIS OVERLOAD
5-axis, 6-axis overload signal is on.
491
SERVO ALARM: 5, 6TH AXIS VRDY ON
5-axis, 6-axis servo amplifier READY signal (DRDY) went off.
494
SERVO ALARM: 5, 6TH AXIS VRDY ON
The axis card ready signal ( MCON) for axes 5 and 6 is off, but the servo amplifier ready signal (DRDY) is not. Alternatively when the power is applied, the DRDY is on and the MCON is not.
495
SERVO ALARM: 5, 6TH AXIS ZERO POINT RETURN
This is a position control circuit error.

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