Note:
The methods of replacing the TMU for different BTS models are similar. The following takes the DTMU in the BTS3012AE as an example to describe how to replace the board.
Remarks:
The DTMUs are installed in slots 0 and 1 of the common subrack.
If the BTS is configured with only one DTMU, replacing the DTMU disrupts all the services processed by the BTS.
If the BTS is configured with two DTMUs, replacing the standby DTMU does not affect the services processed by the BTS. If you need to replace the active DTMU, switch over the active and standby DTMUs, and then replace the former active DTMU to avoid disruption to services.
1) Check the number of DTMUs installed in the BTS.
a. Only one DTMU is installed. Go to 2).
b. Two DTMUs are installed. Go to 10).
2) Log in to the Site Maintenance Terminal System, set the management state of the cells under the BTS to LOCKED. Then, block all the cells under the BTS.
3) Set the DCCU MCB on the DC power distribution box to OFF. That is, power off the common subrack.
4) Remove the cables from the panel of the faulty DTMU.
5) Remove the faulty DTMU.
6) Install the new DTMU in the slot of the faulty one.
7) Reconnect the cables to the panel of the DTMU.
8) Set the DCCU MCB on the DC power distribution box to ON. That is, power on the common subrack.
9) On the Site Maintenance Terminal System, change the management status of the BTS. Set the management status of the cells to UNLOCKED to unblock the cells. The DTMU replacement is complete.
10) Check whether the board to be replaced is the active DTMU or the standby DTMU.
11) Switch over the active and standby DTMUs manually.
12) Remove the cables from the panel of the faulty DTMU.
13) Remove the faulty DTMU.
14) Install the new DTMU in the slot of the faulty one.
15) Reconnect the cables to the panel of the DTMU. The DTMU replacement is complete.