NEC Super Script 4400 Maintenance Manual page 258

Code Description of Error
Optical Unit
L1
(Beam Detecting Error)
L2 Optical Unit
LL Optical Unit
Cause of Error
1. Loose/Broken connection
2. Optical Unit Failure
3. MCTL P.W.B. Failure
MCTL
PD
SGND
+5V-1R
LCN
BDT
20
1. Loose/Broken connection
2. Optical Unit Failure
3. MCTL P.W.B. Failure
MCTL
PD
20
1. Loose/Broken connection
2. Optical Unit Failure
3. DC Power Supply(LVPS)
Failure
4. MCTL P.W.B. Failure
MCTL
PD
3
LCN
20
Clearance Method
1. Check these connections:
a) PDCN connector
b) LCN1 and LCN of MCTL.
2. Replace Optical Unit.
3. Replace MCTL P.W.B.
LDU
PDCN
LCN1 SM
LCN3
1. Check connector LCN3
2. Replace Optical Unit.
3. Replace MCTL P.W.B.
LDU
SCMCLK
1
SCMRDY
2
SCMON
3
GND
4
SM
+24V-1
5
LCN3
1. Check these connections:
a) LCN3
b) PDCN
c) LCN1 and LCN of MCTL.
2. Replace Optical Unit.
3. Replace DC Power Supply(LVPS)
4. Replace MCTL P.W.B.
LDU
PDCN
LCN3
5
LCN1
Service Error Codes
Optical Unit
SM
Optical Unit
SM
Optical Unit
SM
249