Instruction manual
9 - 3
9. TROUBLESHOOTING
Display Name Definition Cause Action
1. Faulty parts in the servo amplifier
Checking method
Alarm (AL.15)
occurs if power is switched on
after disconnection of all cables
but the control circuit power
supply cables.
AL.15 Memory error 2
(EEP-ROM)
EEP-ROM fault
2. The number of write times to EEP-
ROM exceeded 100,000.
Change the servo amplifier.
1. Encoder connector (CN2)
disconnected.
Connect correctly.
2. Encoder fault Change the servo motor.
3. Encoder cable faulty
(Wire breakage or shorted)
Repair or change cable.
AL.16 Encoder error 1
(At power on)
Communication error
occurred between
encoder and servo
amplifier.
4. Encoder cable type (2-wire, 4-wire)
selection was wrong in parameter
setting.
Correct the setting in the fourth digit of
parameter No. PC22.
AL.17 Board error CPU/parts fault
AL.19 Memory error 3
(Flash ROM)
ROM memory fault
Faulty parts in the servo amplifier
Checking method
Alarm (AL.17 or AL.19) occurs if
power is switched on after
disconnection of all cables but the
control circuit power supply cable.
Change the servo amplifier.
AL.1A Motor
combination
error
Wrong combination
of servo anplifier and
servo motor.
Wrong combination of servo amplifier
and servo motor connected.
Use correct combination.
1. Encoder connector (CN2)
disconnected.
Connect correctly.
2. Encoder cable faulty
(Wire breakage or shorted)
Repair or change the cable.
AL.20 Encoder error 2 Communication error
occurred between
encoder and servo
amplifier.
3. Encoder fault Change the servo motor.
1. Power input wires and servo motor
power wires are in contact.
Connect correctly.
2. Sheathes of servo motor power
cables deteriorated, resulting in
ground fault.
Change the cable.
AL.24 Main circuit error Ground fault
occurred at the
servo motor power
(U,V and W phases)
of the servo
amplififer.
3. Main circuit of servo amplifier failed.
Checking method
AL.24 occurs if the servo is
switched on after disconnecting
the U, V, W power cables from
the servo amplifier.
Change the servo amplifier.
1. Voltage drop in encoder
(Battery disconnected.)
After leaving the alarm occurring for a few
minutes, switch power off, then on again.
Always make home position setting again.
2. Battery voltage low
Absolute position
data in error
3. Battery cable or battery is faulty.
Change battery.
Always make home position setting again.
AL.25 Absolute
position erase
Power was switched
on for the first time in
the absolute position
detection system.
4. Home position not set. After leaving the alarm occurring for a few
minutes, switch power off, then on again.
Always make home position setting again.