I have just bought secondhand a set of 3 phones. Two work well but the third the volume is at the maximum yet you can't hear the other person. If you change it to loud speaker it's fine. Does anyone know what the problem is?
Welcome to the Community and thanks for your post!
Sorry for the problems you're having with one of your handsets. Do you know the handset model? You should be able to do a quick >> google search << for the user guide for the model you have. You'll get the number for product support on there and that would be your best bet.