Help Please - Yellow Light on Focus, Logs say "No usable head found"

Hello everyone. I’m trying to see if I can get some help from the community because glowforge support is closed and I’m racing towards a deadline. My glowforge stopped running last night in the middle of a print. It gave me the yellow button and said it was focusing. I cancelled the print. I cleaned all the lenses, mirros, cameras, and fans. Set it back to work.

It ran, but at the end or this run, it went back to the yellow light. The job was completed, but the button was yellow. I did this two more times (I started a job, it gave me the light at the end, I cleaned and continued on). Then it stopped running completely. Now as soon as I turn the glowforge on, I wait about 5 seconds, the fans begin to turn, and then immediately the yellow button comes on.

On the UI, there is no message. It is just stuck on focusing. There is a lot of stuff in the logs, but the first usable error I saw was: No usable head found, unable to cut.

There is also:
Peripheral invalid_head failed to initialize
head_cam: missing sensor
amera_peripheral: Failed to initialize camera


  • I checked the white ribbon. It is secure on both the printer head and on the circuitboard in the back left side of the Glowforge. There are no bent or missing pins.
  • I checked my fans. They are clean and turning smoothly.
  • I checked all my pully wheels and belts. The carriage plate doesn’t seem to get stuck anywhere. My belts are tight. I don’t see any broken wheels.
  • All my lenses and mirrors were cleaned with a lens wipe.
  • I restarted my router, optimized my network, and ran a speed test to make sure I’m getting sufficient internet.

I’m in the middle of a job and I’ve lost almost a day now. Does anybody know what could be wrong? I appreciate all the help.

P.S. uploading pictures in next post.

What about the white ribbon cable itself — not the ends, but everything in-between. Are there any spots where the plastic’s been worn through or crimped, exposing the wiring inside? It’s happened before, and damage to that cable is more likely than the print head itself spontaneously not working.


I had to clean some of it, but from what I can see of the visible parts, the plastic is in tact. I could only check the top side of most of the ribbon and the gaps in the tread on the left, but it looked okay. The only point of worry may be that there is a crease in the ribbon where you can’t pull it up on the laser arm anymore.

I is possible to be the white cable. If there is a cracked bit of copper someplace that causes a glitch. When that happens an intermittent problem becomes more and more common till the bits do not touch and it stops working completely. Usually, there are no visual clues where it has cracked. but replacing the cable usually fixes it. It is most often the black cable rather than the white from what I have seen but it would take someone more familiar with the wiring diagram and the specific cause of each error issue and for that you will need to contact the Mothership (by email)with detailed descriptions and photos.


Is the white cable something replaceable? Or does it go back to glowforge home base?

The specifics would decide that and I would consider either possible. They may see something in the photos that I am missing, that is why we send photos, or they have logs that are more complete than yours. I have not seen those particular error codes.


The cable is not designed to be replaceable and is not sold by Glowforge. Some have sourced them and done it, however.

With a machine in that kind of condition, I think the refurbished deal is something you might consider taking advantage of.


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