Unresponsive GF HD Pro

Hello. I teach high school graphic design and photography and my students and I use the heck out of our Glowforge HD Pro. We've had it a little over 2 years, and have had zero problems, until now. 2 weeks ago, it was cutting some proofgrade medium acrylic when it suddenly stopped cutting with the web interface proclaiming the job finished. It was not. It just stopped and the head hasn't moved on its own since. It soon began kicking "head not found" messages. I submitted a ticket at GF, but their support has been unresponsive.

I followed some online guides to give it a thorough cleaning. In the process, I discovered that the carriage plate fan was quite dirty and the carriage plate looked a bit burnt in spots, so I ordered a new plate assembly, which I've just installed. It is still unresponsive and when I boot it up, besides the sound of the exhaust fan spooling up, nothing happens. The head does not move. It's currently positioned directly beneath the camera.

One odd possible clue... when I pull up the web interface, it shows a glitched out image of the last piece of material it was cutting before it stopped working. That material hasn't been on the crumb tray since the unit failed.

I'm continuing to harangue the support email address as well as our sales rep, but I thought I'd throw this issue out there to see if anyone has any insights.