Nortel DMS-10 Series Installation, Operation And Maintenance Manual page 454

6-16 Section 060-INDP-610 Maintenance Procedures Guide
Procedure 6-2
System low voltage alarm
Step Description
20
If there is a low voltage alarm signal, restore the alarm cable to its original position and
proceed to step 8.
If there is no low voltage alarm signal, proceed to Procedure 6-3 to troubleshoot the alarm
cable. If multiple alarms are reported and the physical conditions that would produce
these alarms do not exist, it is possible that the enhanced alarm cable is causing the error
indications to occur.
21
Verify the condition of the fuse in the power supply for the affected chassis. If the fuse is
okay, proceed to step 9. If the fuse is blown, proceed to step 10.
22
Replace the Power and Alarm Communications PCA using the procedure in the
Hardware Replacement subsection. When finished, proceed to step 12.
23
Replace the fuse. If the fuse holds, proceed to step 12. If the fuse fails, proceed to step
11.
24
Replace the Power Supply assembly in the appropriate chassis using the procedure in the
Hardware Replacement subsection.
25
Verify that the low voltage alarm is no longer active at the maintenance terminal.
Procedure 6-3
Enhanced alarm cable troubleshooting
Step Description
26
Wait for the error indications to clear on the maintenance terminal and the frame fail lamp.
27
Reproduce a thermal alarm by shorting pins 7 and 8 together on the cable connector that
was connected at J16 of the A and B chassis, one at a time.
28
If multiple error indications are triggered, proceed to step 6. If multiple error indications
are not triggered, proceed to step 4.
29
Reproduce a low voltage alarm by shorting pins 9 and 13 together on the cable connector
that was connected at J16 of the A chassis.
297-6201-502 Standard 01.02 September 2000
Sheet 3 of 3