no signal

I connect my recorder with line out to the line at the back side of my computer. Audacity shows some signal but it does not change when i change the outputvolume of my recorder so the signal is not from the music i suppose. I don’t hear any sound and when i press RECORD nothing happens.
What could be the problem? The recorder is a simple digital Boss 4-track machine.

it does not change when i change the outputvolume of my recorder

Are you sure you have output volume controls? They have to specifically say so, not just “Volume.” Most tape machines short of broadcast and recording studio don’t. They have input controls only.

You can put Audacity into diagnostic mode. Right-click on the top sound meters > Start Monitoring. They will wake up and meter the incoming signal all the time without needing to go into record. Monitor goes away if you change any settings or close Audacity.

Are you connected to the blue connection of the desktop soundcard?

You have to tell Audacity how to connect to that, and right there is where you lose me.

This is for connecting a mixer, but it’s very similar connections for connecting a large tape machine.

There is a desperation test. If you get all the settings perfect and it still doesn’t work, make sure the music is getting to the computer by connecting a cable to the computer…

… and touching the tip with your finger while listening. It should buzz. We are intentionally creating sound distortion just as a test. The illustration should buzz on the right (red) channel.

You can test the other end by touching the tape machine cable with your earbuds.

This will not blow your ear off, but it should not be nothing. There should be a very quiet show there.

Let us know which Windows and which Audacity. Also let us know if any of that is not applicable to you because my assumptions were wrong.