Forever Centering/Scanning

Over the course of the last week or so, my GF would occasionally get stuck in “Scanning.” This could be cleared by opening the lid (which showed up in the GFUI) and then closing it again. More recently “occasionally” has become closer to “frequently.” Yesterday, after power-on it got stuck in “Centering.” I checked the WiFi connection, (no change in signal strength or interference from the neighbors’ access points), but restarted things just for drill. I then tried again. this time it got past centering, and I was able to complete a few cuts – but not without “Scanning” difficulties.

Today, it started up just fine – did the “Centering” and initial “Scanning” of the bed as quickly as ever. But it wouldnn’t do any more; it just got hung up in “Scanning.” Restarting it didn’t help. Now it can’t complete the “Centering” operation.

After a quick search of the forum, I had a close look at the five places the black ribbon cable plugs into things. They all look okay to me:

Suggestions for further troubleshooting would be most welcome.

First most basic - is the logo on the top of the laserhead clean? It uses that to confirm it’s centered.

If yes, I know you checked your WiFi for strength, but the :glowforge: doesn’t care about strength it cares about stability. That’s something a staff member can see in the logs on the back-end, but if you want to keep trying things until they get here I’d go through the WiFi checklist.

It’s very likely to be a failing black cable, with your description of cascading failure, but it’s worth checking those little things that are easier to fix!

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Thanks for the suggestions, @deirdrebeth. I had a good look at the GF logo on the top of the laser head. It’s nice and clean. When I noticed this strange behavior beginning to happen, I restarted the WiFi, just to be sure. The problem still came and went sort of randomly.

As yet another test of the WiFi, using a laptop right near the GF, I just ran a 50-ping test against and got this result:

Ping statistics for
Packets: Sent = 50, Received = 50, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 83ms, Maximum = 260ms, Average = 106ms

It would be nice if the ping times were a bit more consistent, but it’s not losing packets.

If I remember correctly, the design of the black ribbon cable has been revised since mine was made back in the day because it tended to fail. Once I heard they decided it was a little too short, I’ve been pretty careful about not opening the GF beyond about half way, but still…

I guess I’ll just need to wait for an analysis.

Again, thanks for the suggestions.

Hello @dehne1,

Thank you for reaching out to us. I’m sorry your Glowforge is having trouble centering and scanning.

I took a look at the logs for your unit and can confirm that the black lid cable is the culprit here. Since you’ve already checked all of the cable connections, and I agree they look fine, the next step is to replace the lid cable.

You can now order the lid cable directly from our shop here: Black Lid Cable

Once you receive the new lid cable you can find installation instructions here: How to Replace the Black Lid Cable

If you run into any issues after replacing the cable or if you have any questions, please don’t hesitate to reach out.

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Thanks, @MorganW. I just ordered the cable. Hopefully that’ll do the trick and I’ll be back in business,

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@dehne1 that’s great! The new cable should fix you right up.

I’m going to go ahead and close this thread. If you have any questions, need assistance during installation, or run into any other trouble please start a new thread or email us at and we’ll be happy to help.

I hope you have a wonderful day!