input/outpit level monitors

I am an infrequent user of Audacity and when I purchased the turntable and software, to covert vinyl to digital it worked without problem.
After some time I have now come back to using it but I cannot seem to get the input and output level monitors to work properly. What am I doing wrong?
I know this is basic stuff, but have pity on me…please. Anyone out there that can offer advice. Thanks

First we need to know whether you’re on Windows, Mac or Linux. Second we need to know what version of Audacity. Third we need to know what you mean by

As a wild guess I’d say you’ve likely changed something in your sound control panel.

– Bill

It would also help to know more about your turntable and how it is connected to your computer - is it, for instance, a USB TT? Model numbers would be helpful.