NEC SV8500 Operation And Maintenance Manual - page 639
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CHAPTER 5
Operation Procedure for System with PIR
Perform the following procedure to confirm the cause of the RGU fuse blown fault.
Start
Visual check: No pin contacting
or backboard melting?
OPE Lamp (green) of
each LC card remains lit?
Replace the blown fuse with a new
one. The fuse is blown again?
Yes
Yes
Yes
Yes
Yes
No
1. Turn ON (UP) the MB key
on the LC card.
2. Remove the card from the PIR.
3. Replace the fuse with a new one.
Turn ON (UP) the MB
keys on all LC cards,
and remove them from the
PIR. (Only PWR cards are
inside the PIR)
Turn ON (UP) the MB
keys on the whole LC cards,
and remove them from the
PIM. (Only PWR cards are
inside the PIR)
The replaced fuse
is blown again?
Perform station-to-station
connections within the PIR.
Is any fuse blown?
Perform station-to-station
connections within the PIR.
Is any fuse blown?
No
No
No
No
No
No
Yes
Yes
No
Fault in LC card that accompanied
the fuse blowing.
Fault of LC card that accompanied
the fuse blowing.
Probable Cause: Not confirmed.
Needs further observation of the fault
There is a short circuit
on the backboard of the PIR.
Fault in LC card that accompanied
the fuse blowing.
Fault of PWR card.
Perform system initialization
after inserting all removed cards.
Fault of LC card
that was removed
Replace the blown fuse
with a new one.
Replace the blown fuse
with a new one.
Replace the PWR card
Yes
Insert the removed cards
one by one (into the PIR).
Is any fuse blown?
The replaced fuse is
blown again?
Fuse is still blown?
No
Yes
The replaced fuse
is blown again?