Turntable input not recognized

After successfully converted my first LP to both MP3 and CD, Audacity 2.2.1 no longer recognizes the audio-technica turntable. Using macOS 10.13.2.

OK, so it worked before, now it doesn’t. Have you changed anything?
Was the turntable switched on when you started Audacity? If not, both the Mac and Audacity may not see it.
In Audacity, have you done Transport > Rescan Audio Devices?
If you go to System Preferences, Sound, Input, do you see the turntable? If you can see it and select it, can you put on a record and see the input level meter reacting?
– Bill

Hi Bill,
Don’t think I changed anything. Have done Rescan Audio Devices. In system preferences I see either Internal microphone or USB Audio CODEC which I believe is the turntable, and that is what is selected. With an LP playing, I see no waveform on audacity.