Had to share a PE770 adventure with all of you. I was stitching along with no problem and then the top thread started breaking and there were several "safety device engaged" episodes. I cleaned out the race, changed the needle, put in a fresh bobbin and still no good. Then I saw there was a major mess on the hook behind plastic piece number 4 (where you thread the machine) and no way to get to it. It was just in for an expensive serving so I wasn't about to go down that road again. Well, after much poking and prodding, I found a video on YouTube where the fellow took apart the entire machine to change a belt. So .... I called hubby in and we proceeded! It was scary, but it worked. Got out a huge gob of thread and now happily stitching away. No more pricey service calls for me!!!