User's Manual

Troubleshooting: SCCP Backplane – continued
FEB 2005 1X SC 4812T Lite BTS Optimization/ATP 6-27
PRELIMINARY
DC Power Problems
Potentially lethal voltage and current levels are routed to
the BTS Equipment.
This test must be carried out with a second person present,
acting in a safety role.
Remove all rings, jewelry, and wrist watches prior to
beginning this test.
WARNING
No DC Input Voltage to SCCP Cage Power Supply Modules
Table 6-28: No DC Input Voltage to Power Supply Module Troubleshooting Procedure
n Step Action
1 Verify the DC Power is applied to the BTS Frame.
2 Determine if any circuit breakers have tripped.
S If a breaker has tripped, proceed to Step 3.
S If breaker does not trip, there is probably a defective module or subassembly within the SCCP
Cage.
– Perform the tests in Table 2-2 to attempt to isolate the module.
3 Remove all cards and modules from the SCCP Cage.
4 Reset the circuit breaker.
S If it does reset, proceed to Step 5.
S If it does not reset or trips again, there is probably a cable or breaker problem within the frame
or DC PDA.
5 Verify that the PS1 and PS2 Circuit Breakers on the DC PDA are functional.
6 Remove the BTS Frame Rear Access Panel (Figure 2-2), and use a voltmeter to determine if the
Input Voltage is being routed to the SCCP Backplane.
Measure the DC Voltage Levels between:
S The PWR_IN_A and PWR_RTN_A Contacts on the extreme right side at the rear of the
backplane.
S The PWR_IN_B and PWR_RTN_B Contacts on the extreme right side at the rear of the
backplane.
NOTE
If the voltage is not present, there is probably a cable or circuit breaker problem within the frame
or DC PDA.
7 If everything appears to be correct, visually inspect the PS1 and PS2 Power Supply Module
Connectors.
table continued on next page
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