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DEFINITY Enterprise Communications Server Release 5
Maintenance and Test for R5vs/si
555-230-123
Issue 1
April 1997
Routine Maintenance Procedures
Page 5-62Troubleshooting Backplane Voltage Problems
5
Troubleshooting Backplane Voltage
Problems
The TN2036 Voltage Range circuit pack is a test tool that allows easy access to
the backplane pins that provide various voltages to control and port slots. Probes
from a voltmeter can be plugged into the access point for the desired voltage
and a ground access point to measure the voltage. This circuit pack itself has
instructions for use printed on the side as well as a listing of the voltage tolerance
range for each voltage on the front panel. The voltages and tolerances are as
follows:
ringing voltage: 75 -> 115 VAC
+12 VDC: 11.4 -> 12.6 VDC
+5 VDC: 4.95 -> 5.35 VDC
-5 VDC: -4.95 -> -5.35 VDC
-48 VDC: -43 -> -53 VDC
neon message waiting voltage: -80 VDC -> -165 VDC
The type of cabinet determines where the circuit is placed to measure the
voltages. For single-carrier cabinets, all voltages except +12 VDC and +5 VDC
can be measured from any port slot. However, the neon message waiting voltage
requires that the system have a TN752 or TN755 Power Unit circuit pack. The
Tape Drive slot is used to measure +12 VDC.
NOTE:
All control circuit packs should be removed from the backplane before this
measurement is made.
The +5 VDC measurement must be made in two separate cabinet locations since
the power unit has two independent +5 VDC outputs [+5 VDC and +5(B) VDC].
Each output supplies a different section of the cabinet with power. For the control
cabinet, make one measurement in the processor slot and another in any port
slot. For an EPN control cabinet, make one measurement in any port slot from 1
to 4 and another in any port slot from 5 to 16. For a port cabinet, make 1
measurement in any port slot from 1 to 6 and another in any port slot from 7 to 18.
Troubleshooting Multimedia Call
Handling (MMCH)
Before troubleshooting any problems associated with the DEFINITY MMCH,
always be sure that the endpoint is operating correctly (audio, video, and data)
by making point-to-point test calls. If possible, make the test calls over the