I just went through what you are going through and I am blessed with having Joann at the LQS where I bought my 6600 a few years ago.....I took it to her yesterday while she was working and she got it FMQ again beautifully by adjusting the tension on the blue bobbin case. In the old days I knew my case was the right tension by taking ahold of the thread in the bobbin and shaking it a bit. If it didn't drop to the floor it was right on or if it wouldn't shake down at all it was to tight. Can't do that anymore but they do get out of adjustment with use and I took mine to classes etc so it got jiggled around a bit. It took some time but she got it going right. Check your manual and it will tell you if you need to turn it right or left. She even knew the page number but I had forgotten my book and she couldn't find the shop one. Good luck, thread and machine is both good. I use Connecting Thread in top and bottom. I forgot to say I use mode 2 which comes up as stitch 11 automatically, number 1 on the pressure foot knob on the top of the machine and the thread tension 5 and of course you already know the feed dogs down. Good luck. I am half done with my quilt FMQing it myself.
Last edited by DarleneW; 05-25-2013 at 08:06 AM.