User's Manual Part 5

ROI-S05751 CORRECTIVE MAINTENANCE
5-47
Chart 5-4 (Cont’d)
Step Procedure
Replacing the DC-DC CONV (Optional).
When the power is supplied to the SELV of the DC-DC CONV (optional)
but the PWR LED of the DC-DC CONV is not lit though the power switch
is on, before replacing the DC-DC CONV, check the conduction of the
fuse in the DC-DC CONV.
1 Referring to Chart 2-1, set the IDU to maintenance ON
condition by LCT
,
2 Set the power switch on the MODEM to Off position,
3 Set the power switch on the DC-DC CONV to Off position,
FG
FG
SELV
!
XIF IN
XIF OUT
IF IN/OUT
TX
RX
RESET
XPIC CTRL
XPIC
PWR
ODU
MD/
CBL
PWR
PULL
AUX/ALM
NMS
NE
SC IN/OUT
EOW
PROTECT
CALL
MMC
MAINT
MEMORY
IDU
NLITE E
LCT
PWR Switch
SELV
PWR LED
−43V/OUT
G
Screw
Screw
SELV
PWR
PULL
PWR
ALM
FUSE (250V/8AH)
− 43V
G
OUT
STD
G
PWR Switch
PWR LED
ALM
ALM
OC-3 IN
OC-3 OUT
ALM
OC-3 IN
OC-3 OUT
ONLINE
ONLINE
4 Disconnect cables connected to the DC-DC CONV as following
order,
(1) Disconnect power supply ca
ble from SELV connector,
(2) Disconnect power supply cable from
−43/OUT connector,
(3) Disconnect ground cable from ground terminal,
(4) Disconnect ALM cable from
ALM terminal,
5 Loosen two screws fixed the DC-DC CONV,
6 Extract the DC-DC CONV from the IDU shelf,
7 Check that the power switch on the spare DC-DC CONV is Off
position
8 Mount the spare DC-DC CONV to the IDU shelf,
9 Tighten two screws to fix the DC-DC CONV,
10 Connect cables to the DC-DC CONV as reversed order in step
4,