Chapter 13 Troubleshooting

13-7

(a) PLC will not start

The CPU OK LED does not turn off even when power is started, nor peripheral units cannot be connected on-line.

Power supply check

AC power supply type
AC power supply voltage (at
the input terminal)
DC power supply voltage (at
the output terminal)
DC power supply type
DC power supply voltage (at
the input terminal)
DC power supply voltage (at
the output terminal)
Fitting between terminal stand
and main unit
YES
YES
NO
NO
NO
YES
131211
Contact our service department
Malfunction due to noise
There is a possibility of power
supply area damage
Occur frequently?
1F
POWER LED is lit
Fatal CPU error
Self-diagnostic error code