You can try some minor diagnosis also i.e.:- get your field tech to check if there is nothing intefering with your TRX in the rack itself.
…may be this will help you
1. your current TRX slot might need to be changed…firstly test your TRX on another spare slot if there is, that will tell you if your TRX is ok or not.
2. if there is a dummy cover next to this affected TRX,take that dummy cover out and then lock on that TRX and try to make calls.