User's Manual Part 5

ROI-S05751 CORRECTIVE MAINTENANCE
5-21
5.1.5 Trouble Shooting Flow
When alarm condition occurs, red alarm LEDs on the IDU are lit except
when there is a power supply failure. Faults can be distinguished using the
LED indicators on the front panel of the IDU. Connect the LCT to the
equipment and check the equipment conditions in according with the flow
chart are shown in Fig. 5-3 to Fig. 5-5.
Is ODU ALM indicator (red) on the
IDU lighted?
YES
Is
IDU ALM indicator
(red) on the IDU
lighted?
NO
YES
Are
both IDU and ODU ALM
indicators (red)
flashing?
Check the IF cable connection and
connectors whether the cable is
open or short circuit.
YES
Is
TX power of the ODU is
indicated normal?
YES
Is
TX Input
indicated normal?
The
IF cable type,
cable length and cable loss are
used standard.
Change the IF
cable to standard.
Is TX power
vary with ATPC manual
control?
NO
Replace the ODU
with a spare.
YES
Replace the ODU with a
spare, if TX power alarm
continues when
temperature is improved.
YES
Is
APC of the ODU is indicated
normal?
NO
NO
YES
Replace the ODU
with a spare.
NO
Is
ODU CPU is indicated
normal?
NO
Reset CPU of the ODU.
Is
ODU ALM is indicated
normal?
NO
Check the RX
section of the ODU.
End
YES
YES
Connect the LCT to the IDU and
check ALARM/STATUS menu.
Check every items whether
indicated status is alarm or normal.
NO
NO
YES
Replace the ODU
with a spare.
Is
LO REF indicated
normal?
NO
YES
Replace the ODU
with a spare.
Is
XREF (MODEM)
indicated normal?
NO
YES
Check the
IDU section.
For XPIC
Fig. 5-3 ODU TX Section Troubleshooting Flowchart