![background image](http://html.mh-extra.com/html/sick/c4-rd/c4-rd_operating-instructions-manual_1264345058.webp)
Table 8: Fault indicator on the sender
LED
Possible cause
Troubleshooting
PWR
ERR
o
o
No operating voltage or operating
voltage is too low or internal fault
b
Check the voltage supply,
b
Switch the voltage supply off and
then on again.
b
If the fault persists, replace the
sender,
.
o
Ö
Red
The voltage was too high when oper‐
ating the sender.
b
Check the voltage supply,
b
Replace the sender,
O
Yellow
Ö
Red
Fault in the supply voltage
b
Check the voltage supply and the
power supply unit,
.
b
Switch the voltage supply off and
then on again.
b
If the fault persists, replace
the defective components,
see "Ordering information",
page 67
.
Ö
Yellow
Ö
Red
The sender identified an internal
fault.
b
Switch the voltage supply off and
then on again.
b
If the fault persists, replace the
sender,
.
o
LED off.
Ö
LED flashes.
O
LED illuminates.
Receiver
Position of LEDs:
see "Receiver indicators", page 12
Table 9: Fault indicator on the receiver
Light emitting diodes
Possible cause
Troubleshooting
OSSD
ERR
Alignment quality
1
2
3
4
O
Red
Ö
Red
Ö
Blue
o
o
o
An internal fault has occurred.
b
Switch the voltage supply
off and then on again.
b
If the fault persists, replace
the receiver,
O
Red
Ö
Red
o
Ö
Blue
o
o
Fault in the supply voltage
b
Check the voltage supply
and the power supply
unit,
.
b
Switch the voltage supply
off and then on again.
b
If the fault persists, replace
the receiver,
10
TROUBLESHOOTING
58
O P E R A T I N G I N S T R U C T I O N S | C4-RD
8025644/19Z2/2021-03-09 | SICK
Subject to change without notice