6 - 9                         6 - 9 
MELSEC-
6   TROUBLESHOOTING 
 
6.6.2 Troubleshooting when the CC-Link/LT side "L ERR." LED of the AJ65SBT-CLB has 
turned on/is flickering 
The CC-Link/LT side "L ERR." 
LED of the AJ65SBT-CLB has 
turned on/is flickering
Is the LED flickering 
or on?
On
Is 
faulty station data 
(RWr) of the AJ65SBT-
CLB on?
YES
Flickering
Consult your local Mitsubishi service 
center or representative, explaining 
a detailed description of the problem. 
Is the 
test mode switch in the 
OFF position?
1: Check for a short, reversed connection, wire breakage, mixed cables,  
    terminating resistors, overall distance, drop line distance (overall drop 
    line length, maximum drop line length) and peripheral environment.
Is all 
station fault (RWr) 
of the AJ65SBT-
CLB on?
Check the remote station that 
turned on in faulty station data.
Power off, then on again.
Is 
the PW 
LED of the CC-Link/
LT remote station 
on?
Is 
the L RUN 
LED of the CC-Link/
LT remote station 
on?
Are 
the remote 
stations connected 
within the control 
range?
Is 
the L ERR. 
LED of the CC-Link/
LT remote station 
off?
Consult your local Mitsubishi 
service center or representative, 
explaining a detailed description 
of the problem.
Refer to the remote station "L 
RUN" LED troubleshooting.
Refer to the remote station "PW" 
LED troubleshooting.
Refer to the remote station "L 
ERR." LED troubleshooting.
Complete
Correct the communication cables.
Consult your local Mitsubishi service 
center or representative, explaining 
a detailed description of the problem.
Consult your local Mitsubishi service 
center or representative, explaining 
a detailed description of the problem.
Check the AJ65SBT-CLB 
side.
Check the CC-Link/LT 
remote station side.
YES
NO
NO
YES
NO
NO
YES
YES
YES
NO
NO
NO
YES
YES
NO
Are there 
any problems on 
the line?
  1
Remove the remote station 
outside the control range.
Increase number of the occupied 
stations.
Reset the last station number 
according to the system.