We've been making quilts with our Innova long arm quilting machine since we bought it 2 years ago. The thread break sensor (TBS) hasn’t ever worked. In between stitching quilts without the TBS (pain in the ass), I’ve tinkered off and on trying to get it working, but last week I put my food down and told myself I HAD to fix it.
The thread break sensor works by flashing a light at a spring that moves with the thread, one cycle per stitch. If the light doesn't flash, it means the spring isn’t cycling because the thread has broken. 99.9% of the time the problem is this light is not shining on the spring properly, but I had eliminated that as a cause of our problem over a year ago.
I knew this was not the problem because I took slow motion videos of the spring moving and the light flashing with every stitch. It moves too fast to see it in real time, but the videos showed that it was NOT missing stitches. If you set the alarm’s tolerance to 10 missed stitches before it goes off, the machine will make ten perfect stitches and shut down. Set it to 5 stitches and it makes 5 stitches before it shuts down, etc.
I pulled the drive housing cover off and there was a junction block dangling there and it happened to have two wires that went to the light. I could not find a place to plug it back in.
I called Innova tech support and got hold of a guy who assumed our problem was the usual one with the light and the spring. Even though I sent him a picture of the junction block and simply asked him where it was supposed to be plugged in, he went through telling me how to do the adjustments of the light and the spring that I had already done a million times, but I humored him for a while. Finally I told him the problem is absolutely not there and I need to know where to plug this junction block in. He coped an attitude and asked me how I knew the problem wasn’t with the check spring/light.
Ha! I have it on video.
After watching the video, he was suddenly nice to me again. Finally, he actually looked at the pictures of the junction block and the drive housing and was shocked. The junction block plugs into the motor’s microprocessor, a good foot away from where it was dangling. No wonder I couldn't find where it went. Someone had unplugged it for some reason, folded all the wires up down in the drive housing and zip tied them together.
He told me where it went, I plugged it back in and ….
Success!!