I have a 7945 that has no handset audio. Every other aspects of the set works including speaker phone and headset.
Steps I've taken
1. Replaced handset and handset cord
2. Replaced the 7945
3. Moved phone to a different jack bypassing all wiring involved and changing the switch port
4. Outed the phone and rebuilt
5. Replaced docking station
6. Outed Webex DI and rebuilt
Steps I've taken
1. Replaced handset and handset cord
2. Replaced the 7945
3. Moved phone to a different jack bypassing all wiring involved and changing the switch port
4. Outed the phone and rebuilt
5. Replaced docking station
6. Outed Webex DI and rebuilt