Scott I had the same problem with my FT-991A. First thing you should do if you haven't is turn on the monitor during a transmit. I'm not familiar with the 950 but assume its menu structure is somewhat similar, if so it will be in the Flist screen, and may be labelled Moni. You should hear the tones while in transmit. In my case I did not. Then I looked through the regular settings and found one that determined where the radio is looking for the sound. If you are using a USB cable to connect be sure its set to USB and not data.
Remember we are using SSB to transmit. Unlike an regular AM signal there is no carrier and if there is no audio there is no modulation in this case no modulation = no signal. I hope this is of some help it took me more than a week to find my problem. Hpefully you'll find yours more quickly.
