We don't support wifi or lan connections to this machine. As for troubleshooting USB connection issues, see below.
Are you using Windows?
If so, have you tried any of the tips given on our website? https://www.simplify3d.com/support/faq/#faq-4630
Are there any other USB devices plugged in?
Can you post the output of entering "listdevices" in the machine control panel's communication log?
"A bird does not sing because it has an answer. It sings because it has a song."