Replacing faulty radio frequency (RF) units
12-7
Wireless Solutions
DualMode 800 Enclosure
Maintenance Manual
MTX08
Replacing the TRU or MCPA shelf
The channels associated with the TRU or MCPA shelf should be out-of-
service during the off-line replacement. This is of major significance if it is
supporting the control channel of the site/sector. In that case, ensure the
system switches to a back-up channel.
Follow the procedure when replacing a TRU or MCPA shelf:
1. At the MTX, put the affected channels out-of-service.
2. Switch off the circuit breaker of the shelf at the RIP.
3. Label and disconnect the cables/connectors connected to the backplane of
the shelf.
4. Remove the TRUs or MCPA modules from the shelf.
5. Loosen the screws mounting the shelf to the RF frame and then remove
the shelf from the frame.
6. Replace a new or known working shelf on to the frame and fix it with the
mounting screws.
7. Replace the TRUs or MCPA modules back to the shelf and fix them with
the mounting screws.
8. Reconnect the cables/connectors to their appropriate locations on the
backplane of the shelf. Ensure that they are connected properly.
9. Switch on the circuit breaker of the shelf at the RIP.
10. At the MTX, put the affected channels in-service.
General rules for replacing a TRU or an MCPA module
The following rules must be followed when replacing a TRU or a MCPA
module:
•
Pull evenly and firmly on the module handle to pull the module out of the
backplane connector. If excessive resistance is felt, stop and investigate
the reason.
•
Slide the module directly and squarely into and out of the shelf guide slot.
•
When inserting a module, carefully line up the module connectors and the
backplane connectors before trying to seat the module. The module
should seat easily into the shelf. Do not force the module into the shelf. If
the connectors are out of alignment, damage to the module and the
backplane will result.
Replacing the TRU
The Transmit Receive Unit (TRU) can be changed with the DC power on.
The channel associated with the TRU should be out-of-service during the off-
line replacement. This is of major significance if it is a control or locate
channel. In that case, ensure the system switches to a back-up channel.
Summary of Contents for DualMode 800
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Page 6: ...vi Publication history Nortel Networks Confidential 411 2051 500 Draft 00 01 November 1999...
Page 82: ...2 20 Periodic maintenance 411 2051 500 Draft 00 01 November 1999...
Page 90: ...3 8 Test equipment and precautions 411 2051 500 Draft 00 01 November 1999...
Page 100: ...5 6 Master Oscillator tests 411 2051 500 Draft 00 01 November 1999...
Page 106: ...6 6 Antenna and transmission line tests 411 2051 500 Draft 00 01 November 1999...
Page 116: ...8 4 Alarm Control Unit ACU tests 411 2051 500 Draft 00 01 November 1999...
Page 138: ...10 2 ICRM tests 411 2051 500 Draft 00 01 November 1999...
Page 200: ...12 10 Enclosure maintenance 411 2051 500 Draft 00 01 November 1999...
Page 208: ...A 8 Appendix A Frequency table 411 2051 500 Draft 00 01 November 1999...
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