Black Cable Hack for Voiding Warranty

There have been a lot of people recently with the dreaded “stuck on centering”, “stuck on focusing”, and “stuck on scanning”. If this happens to you, then first follow the unofficial checklist to rule everything else out: Stuck Centering/Focusing: How to Troubleshoot for potential Lid Cable issues before contacting Support 😲

Basically, rule out dust/dirt, lens, network, and cabling issues. For plenty of people, this will resolve your issues. (Stop reading here!)

If you still have the problem, then contact support. It’s best to include the results of every step from the checklist. Include photos to show the clean interior and cables since that speeds up support’s response. NOTE: Support seems to take 3-4 days to initially respond, and then 24-48 hours between each communication. (“Speedy” is not something you should associate with GlowForge Support.)

If your Glowforge is under warranty, then do what Support says. (Stop reading here, because I’m going to suggest voiding the warranty as an ugly workaround.)

If Support wants you to run other tests, then do it. But expect 1-3 days of turnaround from Support. (Stop reading here! Do what they say!)

If Support says your problem is anything other than the black ribbon cable at the back of the machine, then do what Support says. (Stop reading here! Do what they say!)

If Support says your problem is the black ribbon cable, then order a replacement from them.

NOTE: It will probably take then 1-2 days for Support to email you for your mailing address in order to send you an invoice. And then another 1-2 days for them to send you the invoice after you respond with your mailing address. And if you’re stoopid like me and ask for next-day shipping pricing, then add another 1-2 days for them to respond with the pricing before sending you the invoice link. (And if you don’t pay for next-day, then people are reporting that it takes 7-10 days for shipping.)

On to the hack!

Okay, so that’s all frustration and aggravation. Now for the fun part:

If Support says your problem is the black ribbon cable and you order a new cable and you’re out of warranty, then I have an ugly hack that MIGHT (no guarantee) get a few more uses out of the broken cable. I want to reiterate: this could void your warranty, destroy your GlowForge, and make your dog run away. Do this AT YOUR OWN RISK; don’t blame me if things go very bad. This worked for me, but may not work for you.

The basic problem:

There are different types of flexible printed circuit (FPC) / Flexible Flat Cable (FFC) ribbon cables. (FFC and FPC differ in manufacturing, but for non-techies, both are just flat ribbon cables.) All of these ribbon cables are “flexible”, but that just means they can be bent around stuff. Some are stiff, meaning that you bend around something once and leave it. Others are flimsy, meaning that it can be used with a hinge. (No right angles, but a gentle bending curve is fine.)

All of the electronics in the lid connect to the base through a stiff ribbon cable at the back-center of the machine. This type of ribbon cable is typically NOT used for flexible hinges. The flexing will eventually break the wires. (Why are there so many reports of broken black ribbon cables? I suspect that we all have GFs that are around the same age or same number of uses. And with the holidays, we are all opening, closing, and flexing that stiff cable repeatedly. So they are all breaking at about the same time.) I believe that EVERY GlowForge owner will eventually have this problem.

The big reason it causes the “stuck on centering”: when the wires break, the camera stops working everything else hangs because it’s waiting for the camera. You might get lucky and have it intermittently work; that’s a partial connection of the broken wires. (Before my GF completely stopped working, I had repeatedly reported that my GF seemed slower. Those were intermittent connections of the broken wires and I was just getting lucky that it kind of worked.)

If you look in the back of the GF for the black cable with the lid open, you’ll see that it is mostly straight but it bends around the back hinge. If you open the lid too far, it can stress the cable.

However, that’s probably not the problem. If you close the lid and look at the cable, you’ll see that it bends sharply twice. Once where it connects to the back, and once where it connects to the lid. Those sharp bends are huge stresses on an inflexible wire. In my case, that’s where the wire(s) broke. (NOTE: While I view this as a bad design decision, I don’t think it would have been worth waiting another year for the GF to initially ship. The solution should be to use a flexible ribbon cable and not a stiff cable.)

But there’s a secret with stiff ribbon cables. (That I learned the hard way with way too many raspberry pi cameras.) If you lay the cable straight, then broken wires often have enough of a connection to restore connectivity.

The hack: Bend the wires straight.

First: Never open the lid all the way. We don’t want to stress the cable anymore.

  1. With the POWER OFF, move the arm and head under the camera. This is to give yourself room to work.

  2. Close the lid.

  3. Get a friend – everything from here requires two people.

  4. Have one person hold the lid open about 4 inches. From this point on, you’re not going to open the lid very high so you stop flexing the ribbon cable.

  5. The lower part of the GF’s front is a door that opens downward. You normally open it to remove the crumb tray. Lower the front door (but leave the crumb tray). This is just to give yourself some room to work. Lowering the door gives you another couple of inches.

  6. While one person holds the lid open a few inches, have the 2nd person reach inside to the black cable. NOTE: You are NOT removing the cable and do not try to disconnect or re-seat it. Misaligning the wires is bad and could cause a fire. We’re just going to straighten the wires…

  7. The ribbon cable is stuck to the back wall with some double-back tape. VERY SLOWLY AND CAREFULLY, peel it down about 1/4" inch. Gently bend it forward. And the part that was bent? Gently straighten it. (See, we’re straightening the area where it likely has broken wires. We’re putting in a new bend instead.)

  8. The cable is also stuck to the lid with some double-back tape. Again, gently peel about 1/4", bend it downward, and straighten the old bend.

  9. That’s it! Close the front door, close the lid, and turn on the GF!

Remember: You’re not causing any more damage because you’ve already ordered a replacement cable.

If this worked, then it should power on, focus, center, and return to home, ready for use. (If it didn’t, then stop here and wait for the replacement cable to arrive.)

Now for the ugly part of this hack:

Until you receive the replacement ribbon cable, you cannot open the lid very far ever again because you want to minimize stress on the broken wires. Here’s what works for me:

  1. One person holds the lid open about 2". I know, that’s not very much, but wait…

  2. When you open the lower half of the front door, you have plenty of room to reach in, place material, and remove finished jobs.

Yeah, it takes 2 people and you’re reaching through a small crack. But at least it still works.

Each time you raise the lid – even by a few inches – you could potentially misalign the broken wires. So just assume that every time you open the lid might be the last time it works (until you receive the replacement black cable).

Using this approach, I’ve managed to do a half-dozen jobs and it’s worked for hours. This is not a permanent solution, but it might get you by for the rest of the holiday making season, or at least until the replacement black ribbon cable arrives.

(This goes out to @kateribaybee, @millerwa52182, @jamesdhatch, @akandkk25, @RHLS, @cordioli, @ctmillroy, and everyone else who has reported the dreaded “stuck on centering” and “need a new black cable” problem.)

Update: 4 days later

This cable hack lasted 4 days, but got me through all but one of the last holiday items.

The replacement black cable took about 30 minutes to install. (Stressful, with all of the alignment “make sure the tape is straight” and getting the two side clips inserted is difficult.) But, it works. The black cable DID fix the problem.


This is great ingenuity :slight_smile:
It’s (I think) the 3rd “don’t do this it’ll void your warranty” post made - and all of them are brilliant. I’m out of warranty so it’s good to know this is here in case I ever run into the cable problem


trying this in about 15 minutes…

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no improvement

Not surprising. It’s not wires, it’s copper printed onto the plastic backing. The traces where it flexes are around 0.1mm or less. Once they break, it’s going to be very hard to make reliable contact - although it doesn’t hurt to try while you wait for a replacement.

I also suggest that one selects their assistant for willingness and thin arms. It was a tight squeeze for my normal sized man arms.

I am wondering if the ribbon and connections are not a standard part that could be purchased from an electronic supplier (or if near Orlando, found at Skycraft as that is just the sort of stuff that they have bunches of though you sort of have to go there to look) If someone in Orlando could go and look they might get enough for a hundred such ribbons and be a supplier for the rest of folk not living there.

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No, it is a custom made part that slots precisely into the connector on the back of the machine, and the connectors on the ends of the boards down each side of the lid. It breaks out different connections from the main section to each side.


I agree.

I own pinball machines which handle wire flex better than this high-tech laser cutter.


OK. I’m going to make sure I never have the “Broken Black Cable” problem.
I’m going to order a spare - that will insure the original will never break.
How do I order one? I don’t see it listed in the store.


Hi @icronkite,

As far as I know, it’s a special invoice from GF Support. So they have to authorize one. The cables are about $20 with $9 shipping (for 7-10 day delivery). A few people have reported that they can order 2 cables. (Wish I had done that.) And I requested next-day delivery (which really means 1-2 days AFTER they mail it, and GF Support still haven’t put it in the mail as far as I can tell).

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As things stand, you can only order one if support determines you need one.

Why not just grab a 2x4x24" piece of wood and slide it under the lid and eliminate the 2nd person? :slight_smile:


seems like we should be able to, at worst case, cut the ends off of an existing cable… And splice in flexible (stranded) cable and eliminate the issue. I don’t care how pretty it looks if it kills the problem.


that is essentially what I did.


i’m not saying it is impossible but looking at the existing cable, that seems like a tall order.

Did that change recently? I bought a spare a couple of weeks after I got my unit in September and they sent it no questions asked (paid for it of course).

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Mine was a long time ago and was fixed!!! not the cable, to be honest, I bearably open to the point that the cable is stressed out anyway! But thanks! :slight_smile:

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Hi folks,

This cable hack lasted 4 days, but got me through all but one of the last holiday items.

The replacement black cable took about 30 minutes to install. (Stressful, with all of the alignment “make sure the tape is straight” and getting the two side clips inserted is difficult.) But, it works. The black cable DID fix the problem.