A few weeks ago, I was quilting on my longarm and I broke a needle. Still not sure what happened - I blinked, hit the ruler, and the needle shattered into 3 pieces. Found 2 of the pieces, and heard the third hit the floor, so at least I knew it wasn't jammed in the machine (still haven't found that elusive third piece). But, that hit threw the timing out on the machine, just enough that thread started to break, particularly when stitching in one direction. I pushed through the current quilt, because I had a deadline. But the next one was a pantograph that the machine now hated. After breaking the thread 3 times in a 6" span, I decided I needed to suck it up and take the machine in for a tune up.
Fortunately, she was able to fit me right in, and I had the machine back in 2 days. And it stitches like a DREAM now. Better than it has since I got it, in fact. The dealer said the timing wasn't out by much, but apparently it was more than enough to completely mess with the stitching. I'm so happy today. Two quilts completed without a single broken thread. I think that's a record for me!