GF Basic shuts off in middle of a print. Sometimes get an Interlock open alert

I put in a ticket but I figured that I’d post something here to just to get some feedback. I’ve had my GF for 3 years. No issues. I moved into an older house 9 months ago. I have not had any issues with the GF up until now. I moved the GF from one side of my computer room to the other. The reason was because I installed an AC unit in the window where the GF was. (It’s the side of the house so it looks better.) I moved the GF to the other side of the room so that I could vent it the other window in the room. However, the power cord does not reach the outlet. I plugged it into one of those thick 50’ HDX orange extension cords from Home Depot and ran it to the same outlet it’s always been in. Now when I try to start up a print, it’ll go for about a minute and then just shut off. It’s not tripping the breaker. I thought maybe having the AC running was causing a huge voltage drop so I unplugged it while running the GF. A meter shows the voltage to be between 118 and 120. The GF needs 100-240 so it’s not the voltage.

One time it shut off after a print and right after the fans were spinning down. I looked at the computer and it displayed an Interlock open alert. (It was a short print, like 10 seconds. So it’s not like it’s overheating or anything.) It’s really cool in the room.

After it shuts off I have to leave it for like an hour before it turns on. Not sure why. Is there some kind of fuse that needs to self-reset? I’ve checked the power cord. I’ve made sure the door’s are securely shut. I’ve removed the head and made sure that the ribbon cable is firmly seated.

We also added a few other AC units downstairs since I last ran the GF so I wonder if all this extra power draw on the house’s circuit is causing an issue. Does anyone know if this is a thing? Does the GF shut off and stay off for an extended period of time if the voltage drops or is all that coincidence and my GF is on the way out?

I wonder if this is your problem? According to the GF Manual, "Plug the Glowforge into a grounded wall outlet with 800 watts of power available. Make sure you connect the printer directly to a wall outlet and not a surge protector or power strip." Maybe just the fact it’s connected to an extension cord might be causing the issue?

Do you know what gauge of wire is in the extension cord?

16 ga

This is so weird. The standard 6’ power cord does not reach the outlet by the wall. That’s why I was using an extension cord to plug into the one on the other side of the room where it was. I just fond that I have a pretty beefy 10’ medical grade power cord. I plugged that into an outlet that I can now reach without having to use the 50’ one. The GF turned on and went through it’s startup sequence no problem. I loaded up my file. I was just about to hit the print button when I realized that I left the AC running. I figured I’d better turn it off. (Even though it’s on another socket. However, I bet everything in this room is on the same breaker.) As soon as I turned off the AC, the GF shut off!

This house is from 1956 so I think the power is a little janky. I think I got lucky for 9 months, but now with ACs and stuff running it’s becoming a problem. Still not sure why shutting off the AC would make the GF shut off. Maybe the GF just doesn’t like blips on the line. In-rush current, etc.

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That may be the issue. Your house wiring is probably 14 gauge and if you are using an extension you may want to go to 12.

I’m at a loss. I shut off all the AC units in the house. So it’s just like it was before I got them. I have the GF plugged in an outlet with that 10’ medical grade power cable. The GF turned on and did it’s startup sequence. Once it got to idle, it just shut off.

I even checked the outlet with a tester. 120V and properly grounded.

Were you using an extension cord before you moved it?

I don’t know what a medical grade power cord is but the wire gauge could be a factor if it was working properly before switching to an extension cord.

When it was on the other side of the room under the other window it was plugged in the wall with the regular power cord. Now it’s plugged in another outlet on the other side of the room using a 10’ power cord. Not sure why another 4’ on a power cord would cause the unit to just shut down.

I’m no electrician by any stretch, but could it be that the outlet is bad somehow? Not the cord, nor the GF, but the outlet?

*oops…“I even checked the outlet with a tester. 120V and properly grounded.”

sorry…nevvverrrrr mind.

Well one way to prove the machine is not at fault is to drag it back over to the original outlet and try it there again with just the original cord.

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I might be pretty cautious of the situation with older wiring involved. You could have arcing problems etc. Sometimes these can be so minute that they won’t actually trip the circuit.

Everyone here is really helpful, but posting in Problems and Support opens up ‘another’ ticket and slows down the overall time in getting back to everyone. Maybe next time posting in Everything Else would be a good spot!


I was thinking that but what a pain! I moved all the furniture around to accommodate moving the GF to the other window. I’m going to have to I guess.

I did not realize that. I figured I’d post something here to get some feedback and maybe some ideas to try while I waited for support to get back to me.

Yes a pain for sure but one way to figure out where the issue may be.

Hello @ryemac3 - I’m sorry to hear you’re having this power trouble.

Based on the discussion that’s gone on in this thread, I do think the best thing to try here would be trying that other outlet with the original cable and seeing how the printer performs.

There could be an issue with the printer’s power itself, and trying the printer in another outlet will be the best for us to narrow this down.

Let me know how it goes!

OK, I moved the GF back to the original outlet with the original cable and did a 2 minute cut on some Draftbaord with no issues. I guess there is just something with that other outlet. Maybe the run that it is on it is excessively long; similar to plugging it into the 50’ extension cord. Who knows with this old house? That outlet might be connected to stuff downstairs for all I know!

Thanks everyone for all the help!

Ugh! I spoke too soon. I was typing up the above reply and the unit just shut off! I do not know what to do now.

I just did another cut. Took about a minute. No issues. It cooled down and then was at idle for about 2 minutes maybe. And then it just shut off. UI says “Interlock open”.

Hi @ryemac3. Thank you for getting back to us with the current state of the power issue and the Interlock error message. I saw you had opened an email support request for this as well. I just sent you a response through that email ticket since the best next steps to resolve this can include confirmation of some private information. Can you check your inbox, and reply to my email at your earliest convenience? Once confirmed received, I will close this thread, and will continue any next best steps through email. Thank you!