1. Website: http://www.repair-fanuc.com/
Fanuc 10/11 Master Board Alarm Codes
CNC Diagnostic
Fanuc 10/11
Master Board Alarm Codes
LED
Display Alarm Description Repair
A. MDI connection failure
Check fiber optic cable connection between control and
MDI/CRT unit.
Replace Master Board, MDI Pcb, or fiber optic cable, small
power supply front panel.
C. MDI Failure
Connection Unit for operators panel or connecting cable is
defective.
F.
Connection Failure of
connection unit or I/O cards D1
- D3 Check fiber optic cable connections between these units.
Replace Master PCB, connection unit, I/O board, Fiber optic
cable
Failed I/O module in I/O base unit.
H. Connection Failure I/O Connection Unit 2 or its connecting cable defective.
c.
Transfer error through fiber
optic cable
Check Front Panel Power Supply, Replace Master PCB, MDI
PCB, Connection Unit PCB, I/O Unit , Fiber Optic Cable
J.
PC or interface converter not
functioning
Check PC-ROM cassette, PC RAM Board, or interface
converter is mounted on Master PCB.
L. Waiting for PC ready Replace PC ROM, PC ROM Cassette or PC RAM Board.

2. b. RAM check error Replace Master PCB or ROM/RAM board
8 RAM Check
Check Power Supply, Clear Memory and Reload parameters.
Replace Master Board.
d. Power Supply Ready Signal Replace Power Supply, Master PCB
E. System Error Replace Master PCB,Rom PCB or NC Software ROM
Wrong option parameters
No message on CRT- Clear memory
O. IPL Mode
1 Normal Operation
4 Bad ACP Replace ACP daughter board
Fanuc 10/ 11 Alarm Codes
CNC DIAGNOSTIC
SV 000
Tachogenerator
Disconnect
M Series Servo - Check the connection to the motor -
Remove wires from terminals 5,6,7,8 - measure between 5
and 7 or 6 and 8 should read a short. Check for tach
feedback at check terminals CH2 and CH3.
AC Servo -
Check the
connection to the
motor - Remove
wires from
terminals 5,6,7 -
measure between
each of the wires,
they should all
read the approx
same and should
be low resistance
SV 001 Motor Overload
M Series Servo - Reset overload, Check the servo
transformer thermostat
AC Servo -
Check the
thermostat on the
servo transformer
and the heat fin
SV 002
Velocity Unit
Breaker Off
M Series Servo - Turn off power and reset breaker
Alarm message
not displayed for

3. AC Servo
SV 003
Excess Current in
Servo
M Series Servo - Disconnect servo motor and check for
short to ground. Check for short circuit on transistors. Bad
servo drive board
AC Servo -
Disconnect servo
motor and check
for short to
ground. Check for
short circuit on
transistors. Bad
servo drive board
SV 004
Excess Voltage in
Servo
M Series Servo - Check input voltage. Check servo motor
for short circuit. Replace servo control pcb
AC Servo -
Check input
voltage. Check
servo motor for
short circuit.
Replace servo
control pcb
SV 005
Excess Discharge
Current
M Series Servo - Discharge transistor or pcb is defective
AC Servo -
Discharge
transistor or pcb
is defective
SV 006
Velocity Unit
Power to Low
M Series Servo - Incoming power is to low. Check voltage
on pins 1 and 2, and 2 and 3 on CNC2 for 19 volts ac.
Replace pcb
AC Servo -
Incoming power
is to low. Check
voltage on pins 1
and 2, and 2 and
3 on CNC2 for 19
volts ac. Replace
pcb. Check 5v
fuse.
SV 008
Excess Error
(Stop)
Check parameters 1828 - 1830. Check incoming voltage.
Master board may be bad.
Check
parameters 1828
- 1830. Check
incoming voltage.
Master
board may be
bad.
SV 009
Excess Error
(Moving)
Check parameters 1828 - 1830. Check incoming voltage.
Master board may be bad.Check for mechanical bind.
Check
parameters 1828
- 1830. Check
incoming voltage.
Master
board may be
bad.Check for
mechanical bind.
SV 010
Excess Drift
Compensation
Check connections to motor. Check if parameter 1834
exceeds 500. Master board may be bad
Check
connections to
motor. Check if
parameter 1834
exceeds 500.
Master board
may be bad
SV 011 LSI Overflow
Check parameters 1826,1825,1820,1816. Pulse coder may
be defective. Master board may be defective.
Check
parameters
1826,1825,1820,
1816. Pulse
coder may be
defective. Master
board may be
defective.

4. SV 012
Motion Value
Overflow
Check CMR parameter or feedrate setting failure
Check CMR
parameter or
feedrate setting
failure
SV 013
Improper V-Ready
Off
M Series Servo - Check for a 100vac between terminals 3
and 4. Check fuse breaker is not tripped
AC Servo -
Check for a
100vac between
terminals 3 and 4.
Check fuse
breaker is not
tripped
SV 014
Improper V-Ready
On
Velocity control ready signal VRDY was turned on when the
position control ready signal PRDY is turned off
Velocity control
ready signal
VRDY was turned
on when the
position control
ready signal
PRDY is turned
off
SV 015
Pulse Coder
Disconnect
Broken cable to Pulse Coder. Bad pulse coder. Master
board may be defective.
Broken cable to
Pulse Coder. Bad
pulse coder.
Master board
may be defective.
SV 017
ILL Position
Control LSI
A position control LSI fault was detected
A position control
LSI fault was
detected
SV 018
Unfit DSOG
Frequency
Check connection to resolver. Check gain and phase shift.
Position detector is bad. Inductosyn/Resolver pcb is bad.
Check connection
to resolver.
Check gain and
phase shift.
Position detector
is bad.
Inductosyn/Resol
ver pcb is bad.
SV 019
Unfit Pulse of
Pulse Coder
An error was detected in the feedback pulse from the pulse
coder
An error was
detected in the
feedback pulse
from the pulse
coder
SV 020
Unfit Phase Shift
Value
Check connection to resolver. Check gain and phase shift.
Position detector is bad. Inductosyn/Resolver pcb is bad.
Check connection
to resolver.
Check gain and
phase shift.
Position detector
is bad.
Inductosyn/Resol
ver pcb is bad.
SV 021
Unfit Pulse Coder
1 Rev On
The one revolution signal from the pulse coder was turned
on at an abnormal position.
The one
revolution signal
from the pulse
coder was turned
on at an
abnormal
position.
SV 022
Pulse Coder 1
Rev Missing
The one revolution signal from the pulse coder was not
turned on within the allowable tme
The one
revolution signal
from the pulse
coder was not
turned on within

5. the allowable tme
SV 023 SV Overload Servomotor was overloaded
Servomotor was
overloaded
SV 025 V Ready On
Velocity control ready signal VRDY was turned on instead of
being turned off when the servo control was turned on.
Velocity control
ready signal
VRDY was turned
on instead of
being turned off
when the servo
control was
turned on.
SV 026
Illegal Axis
Arrange
Parameter #1023 for the servo axis arrangment was not set
properly
Parameter #1023
for the servo axis
arrangment was
not set properly
SV 030 Emergency Stop Emergency stop was applied
Emergency stop
was applied
OT 001
"+" Overtravel
(Soft 1)
OT 002
"-" Overtravel
(Soft 1)
OT 003
"+" Overtravel
(Soft 2)
OT 004
"-" Overtravel
(Soft 2)
OT 005
"+"Overtravel
(Soft 3)
OT 006
"-" Overtravel
(Soft 3)
OT 007
"+" Overtravel
(Hard)
OT 008
"-" Overtravel
(Hard)
OT 021
"+" Overtravel
(Pre-Check)
OT 022
"-" Overtravel
(Pre-Check)
OT 100 Spindle Alarm Spindle motor alarm signal turned on
OT 101
Spindle Motor
Overheat
Spindle motor is overheated. Check Fan on spindle mo
OT 102
Excess Velocity
Error
A deviation is excessive between commanded and actual
velocity of spindle motor. Transistor module bad. Spindle
motor feedback sensor bad.
OT 103 Fuse F7 Blown Check Fuse F7. Check transistor modules
OT 104
Fuse F1,F2, or F3
Blown
Check Fuse F1,F2, and F3
OT 105
Fuse AF2 or AF3
Blown
Check AF2 and AF3. Defective PCB
OT 106
Excess Velocity
(Analog)
Spindle motor speed exceeded the max rating.
OT 107
Excess Velocity
(Digital)
Spindle motor speed exceeded the max rating.
OT 108 Voltage (+24V) Check 24Volts, Check voltage selector switch

6. Too High
OT 109
Power
Semiconductor
Overload
Power semiconductor overheat Check Fan on spindle drive
OT 110
Voltage (+15V)
Too Low
Check 15V test pin on spindle board.Check Fuses. Replace
spindle Board
OT 111
Voltage
Excess(DC Link)
The voltage on the DC Link is to high. Check incoming
voltage.
OT 112
Current Excess
(DC Link)
High current. Check motor for short. Check transistors.
OT 113 CPU Error Replace spindle board
OT 114 Rom Error Rom ics defective. Replace spindle board.
OT 115 Option Alarm Auxiliary alarm for spindle motor.
OT 116
Disconnection
Pulse Coder
Bad Pulse Coder. Broken Cable.
Fanuc AC Spindle Alarm Codes
AC Spindle Drive Faults
Alarm List for the following Drives:
Model 1 A06B-6052-H001
Model 2 A06B-6052-H002
Model 3 A06B-6052-H003
Alarm List for the following Drives:
Model 3 thru Model 40 A06B-6044-Hxxx
Alarm
#
Led Display Content of Alarms
8 4 2 1
Alarm
#
Led Display Content of Alarms
8 4 2 1
1 o Motor Overheat
2 o Speed deviates from commanded speed
3 o o Regenerative fault
6 o o Excess Motor Speed Analog
7 o o o Excess Motor Speed Digital
8 o Voltage higher than specified
9 o o Radiator for power semiconductor overheat
10 o o +15Volt Supply is low
11 o o o DC Link voltage is high
12 o o DC Link current is high
13 o o o CPU and peripheral parts are defective
14 o o o ROM is defective

7. 1 o Motor Overheat
2 o Speed deviates from commanded speed
3 o o Fuse F7in DC link is blown out.
4 o Fuses F1,F2,F3 for AC input blown out.
5 o o Fuses AF2 or AF3 on PCB are blown out.
6 o o Excess Motor Speed Analog
7 o o o Excess Motor Speed Digital
8 o Voltage higher than specified (24v)
9 o o Radiator for power semiconductor overheat
10 o o +15Volt Supply is low
11 o o o DC Link voltage is high
12 o o DC Link current is high
13 o o o CPU and peripheral parts are defective
14 o o o ROM is defective
15 o o o o Option circuit fault.
Digital AC Spindle Drive
Alarm List for the following drives:
Model 3 thru 22 A06B-6055-Hxxx
Alarm Display Alarm Content
AL-01 Motor Overheated
AL-02 Speed deviates from commanded speed
AL-03 Fuse F7in DC link is blown out.
AL-04 Fuses F1,F2,F3 for AC input blown out.
AL-06 Excess Motor Speed Analog
AL-07 Excess Motor Speed Digital
AL-08 Voltage higher than specified (24v)
AL-09 Radiator for power semiconductor overheat
AL-10 +15v power supply is abnormally low
AL-11 DC Link voltage is high
AL-12 DC Link current is high
AL-13 Data memory for CPU abnormal
AL-16 RAM in NVRAM is abnormal
AL-17 ROM in NVRAM is abnormal
AL-18 Check sum alarm of ROM
AL-19 Excessive alarm of U phase current detection circuit offset
AL-20 Excessive alarm of V phase current detection circuit offset
AL-21 Excessive alarm of velocity command circuit offset.
AL-22 Excessive alarm of velocity detection circuit offset.
AL-23 Excessive alarm of ER circuit offset.
AL-14 ROM is abnormal
AL-15 Spindle selection control circuit is abnormal.
Alarm List for the following drives:

8. Model 1S thru 3S A06B-6059-Hxxx
Alarm # Meaning
AL-01 Motor Overheat
AL-02 Speed deviates from commanded speed
AL-03 24v Fuse is blown. (before PCB edition 09A)
AL-04
AL-05
AL-06 Excess Motor Speed Analog
AL-07 Excess Motor Speed Digital
AL-08 Over voltage
AL-09 Overheat of radiator
AL-10 Low voltage of input power.
AL-11 Excessive high voltage of DC link
AL-12 Abnormal current of DC link
AL-13-15
AL-16-23 Defective arithmetic circuit and peripheral
circuit
No
indication
Defective ROM
Alarm List for the following drives:
Model 6S-26S A06B-6059-Hxxx
Alarm # Meaning
AL-01 Motor Overheat
AL-02 Speed deviates from commanded speed
AL-03 24v Fuse is blown. (before PCB edition 09A)
AL-04 Open phase of input power.
AL-05
AL-06 Excess Motor Speed Analog
AL-07 Excess Motor Speed Digital
AL-08 Over voltage
AL-09 Overheat of radiator
AL-10 Low voltage of input power.
AL-11 Excessive high voltage of DC link
AL-12 Abnormal current of DC link
AL-13 Defective arithmetic circuit
AL-14 Defective ROM
AL-15 Defective optional circuit.
AL-16-23 Defective arithmetic circuit and peripheral
circuit
No
indication
Defective ROM