First off, anytime you have problems with only one location, there's usually nothing wrong with your machine. You need to make sure that you or your fax machine is dialing the right phone number AND that phone number is being answered by their fax machine. You can test by dialing manually using a handset. Listen to see if a fax machine answers (high pitch tone). If not, check to make sure that you have the right phone number. Note - don't trust that the number you see printed on a cover sheet or listed on your transaction report is the actual telephone number of the sender's fax machine. Cover sheets are sometimes outdated and the numbers programmed in the machine may not be right. The machine may have been moved or the phone number changed.