I had a heck of a time this morning with my Glowforge Pro. For about an hour I could not resolve the “head not found” error message. I tried everything, including making sure the belts were aligned and everything was cleaned.
And then I saw it - a beam of sunlight was hitting right where the camera is, so when the head was directly under the camera, the top of it was also being hit by the sun-beam which probably over saturated the sensor of the camera. However because there’s no “The Day Star, IT BURNS!” Error message, it posted Head not found.
I blocked the sun beam and the Glowforge was a happy laser cutter once again, ready to incinerate its enemies, sorry… materials.
So, if you see this message and all else fails, check for sunlight. You never know!
in front of a window, and to much light can mess with the camera.