Went to use my GF yesterday and it’s back to the same issue I was having before.
GF turns on, does it calibration (clicking sounds) and then app indicates it’s in scanning mode. No movement of laser head, just a fan/humming noise after.
I’ve tried to start it with the crumb tray out, as that worked last time but no go. I’ve cleaned out the tray thoroughly, started it with no material loaded and with some loaded as well. I’ve repositioned the laser head, reseated the ribbon and lenses and cleaned everything. I’ve tried starting and restarting numerous times, tried different web browsers, personal hotspot and it just goes back to scanning every time.
I’m getting super frustrated. Somebody please help!
Ok so I tried checking the connections of the lid ribbons and removing the laser head and checking the ribbon connections inside. There’s a small L-shaped ribbon near the bottom of the head beside the small fan. It got bent up from reseating the head onto the magnets. I bent it back flat and when I turned the GF back on it calibrated and then I had head movement and it said ready to print. I was going to try doing a print and opened up the lid to change the material and once again it sent the app into scanning. 
I was so excited that I had figured out the issue but once again I’m back the scanning mode of death.
Just from trouble shooting it seems I have either a connection issue with the laser head, lid or both. I’m going to do another check of the ribbon connections and see if I can get it functioning again.
The details are good, they can help Support to pinpoint what the problem is. Good luck, I hope you (or they) find it quickly. 
Thanks for letting us know about the additional troubleshooting you performed. I pulled the logs from your Glowforge to investigate your report, and unfortunately, it looks like your unit is experiencing an issue that we can’t resolve remotely. I want you to have a reliable unit, so I’m recommending we replace or repair this one. I’ll be in touch via email to sort out the details. I’m so sorry about the bad news.