Handset problem I have a Norstar M7100 and when I received a call I can hear the caller but the caller can't hear me! cam you help?

It sounds like you have a defective handset cord or handset. First, at your phone, switch your handset with another phones handset that you know for sure works. From your phone make a test call. If the caller can now hear you, the original handset from your phone is defective. If the caller still can not hear you, switch your handset cord with another handset cord from another phone that you know works. From your phone make another test call. If the caller can hear you, then your original handset cord is defective. You can purchase another handset cord from your local office supply store. Your phone uses a standard handset cord. It may be difficult to match the original color of your handset cord. Be sure to take your defective handset cord with you, so you can try to match the color. If the caller still does not hear you. Put your original handset and original handset cord back on your phone. Then plug your phone in to another wall jack, that you know works with another phone. The other phone needs to be an identical phone to yours (same number of buttons and same model number. The model number can be found under the phone). Wait approximately 90 seconds, sometimes longer, after you plug your phone into the other wall jack. Now, make another test call from your phone. If the caller can now hear you from your phone with it plugged into another working jack, then you have a defective station port or jack where your phone was originally plugged in at. If the caller still can not hear then you have a defective phone.