Service Manual

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GSM-205-523

Replacing a CTU

31st Oct 01

Maintenance Information: Horizon

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indoor

68P02902W09-B

CONTROLLED INTRODUCTION

Maint. 2–21

Fitting replacement CTU

To fit a replacement CTU:

1. Ensure that the correct CTU push-on/push-off circuit breaker button on the

CBM has been pressed to the out (off) position.

2. Ensure that the transmit RF power of the correct CTU has been locked

using the shutdown_device command at the OMC-R or from a PC

connected to the MCUF.

3. Insert replacement CTU module, taking care to locate the module on the

guide rails. Press firmly into place.

4. Tighten both module attachment screws to the correct torque (see

Overview of replacement procedures), using an M4 Torx driver.

5. Attach coax cable to appropriate Tx block or feedthrough plate for the

CTU. Tighten to correct torque (see Overview of replacement

procedures).

NOTE

The Tx cable has a 90° SMA connector at one end, and a

straight SMA connector at the other end. The 90° end is

designed for connection to the Tx port of a CTU.

6. Screw the coaxial cable onto the Tx OUT SMA connector at the top of the

CTU front panel. Tighten to correct torque (see Overview of replacement

procedures).

7. Press and release the appropriate CTU circuit breaker button on the CBM.

The RADIO STATUS LED will flash green for about two minutes, and then

remain lit.

CAUTION

If both RADIO STATUS and Tx STATUS LEDs are

flashing, the bootcode is downloading into non-volatile

memory for software upgrade. Power should not be

removed, nor the cabinet reset, until downloading has

been completed, as this will corrupt the non-volatile

memory. If bootcode is corrupted, contact Motorola

Customer Network Resolution Centre requesting the

bootcode restoration procedure and the appropriate

bootcode file.

8. Enable the CTU transmit RF power by using the ins_device command

at the OMC-R or from a PC connected to the MCUF. The Tx STATUS LED

(yellow) will be lit if the CTU is transmitting.

9. Notify the OMC-R of base station availability and log the maintenance

activity.