User Manual

CCP Backplane Troubleshooting – continued

SC4812ET BTS Optimization/ATP — CDMA LMF

Jan 2002

6-18

No DC Input Voltage to Power Supply Module

Follow the procedure in Table 6-23 for problems with DC input voltage.

Table 6-23: No DC Input Voltage to Power Supply Module

Step Action

1 Verify DC power is applied to the BTS frame. Verify there are no breakers tripped.

* IMPORTANT

If a breaker has tripped, remove all modules from the applicable shelf supplied by the breaker and

attempt to reset it.

– If breaker trips again, there is probably a cable or breaker problem within the frame.

– If breaker does not trip, there is probably a defective module or sub–assembly within the

shelf.

2 Verify that the C–CCP shelf breaker on the BTS frame breaker panel is functional.

3 Use a voltmeter to determine if the input voltage is being routed to the C–CCP backplane by

measuring the DC voltage level on the PWR_IN cable.

– If the voltage is not present, there is probably a cable or breaker problem within the frame.

– If the voltage is present at the connector, reconnect and measure the level at the “VCC” power

feed clip on the distribution backplane. If the voltage is correct at the power clip, inspect the

clip for damage.

4 If everything appears to be correct, visually inspect the power supply module connectors.

5 Replace the power supply module with a known good module.

6 If steps 1 through 4 fail to indicate a problem, the C–CCP backplane failure (possibly an open

trace) has occurred.