Power Supply Fault - NEC Univerge SV8500 Operation And Maintenance Manual

4.9

Power Supply Fault

This section explains the fault repair procedure when any of the faults shown in Table 5-9 occur.
FAULTY SITUATION
When the "RGU" / "-48V" Fuse has Blown
DC-DC PWR Circuit Card Breaker OFF, Fault in PWR Supply
Fault of Alarm Lamps on DC-DC PWR Circuit Card
4.9.1 Check Point
When repairing a power supply fault, consider the following items:
(1) Before checking the system, check the Rectifier, Battery, and Power cables.
(2) PWR circuit card is equipped with the circuits to supply ringing signal and howler tone. When a fault oc-
curs that causes the bell of the telephone not to ring, or howler tone cannot be heard, etc., check the alarm
lamp on the PWR circuit card.
CHAPTER 5
Table 5-9 PWR Supply Fault Situation
– 645 –
Operation Procedure for System with PIR
REFERENCE SECTION
Section 4.9.2, Fuse Blown Fault
Section 4.9.3, Circuit Breaker OFF Fault in PWR
Supply
Section 4.9.4, Fault of Alarm Lamps on PWR Supply