I posted last under the tension update topic. However, my problem is not tension. Thus the new topic.
Recap: I am sewing merrily along and get a birds nest/thread jam under the throat plate. I remove all thread I can see and rethread, and within a few stitches it happens all over again, and again, and again, and again. Then it magically starts sewing like a dream for awhile. It happens a LOT with metallics. It also happens with the wider stitches. I get a lot of thread caught in the thread cutter (the assembly at the left under the throat plate, with the little metal triangle at the tip).
I talked to my dealer and asked him to show me how to use the hook cleaning tool in the new accessory box. He hasn't received instructions on that yet. He is going to technician's training in 3 weeks and will find out then how to use it.
He showed me how to clean the thread cutter. You go into Set-Up and select the tool icon in the middle of the 2nd row of icons. On my 830, you see three numbers, 1, 2 and 3 at the left. #2 is pre-selected, with cleaning instruction text. When I touch #1 or #3, you can move the thread cutter out to the right, to remove caught threads easier.
Also, he told me that some of his customers with thread problems have had the "horseshoe spring" in the bobbin assembly become disengaged. The "horseshoe spring" sits under the bobbin. It is a pear-shaped gray metal thing. It is designed to prevent the bobbin from keeping on spinning (and releasing thread) when you are sewing at high speeds and stop suddenly. If it comes out of one of those brackets (disengaged) you get thread jams. He said it is held in place with 4 little brackets (at 12, 3, 6 and 9 o'clock). You can take it out easily, but you have to put it back in right. The fat part of the pear needs to point to 3 o'clock, and the narrow end of the pear shape needs to point to the 9 o'clock side. You have to make sure it is held in place under those brackets. Also, you need to make sure when you replace it that the spring part is out toward the bobbin - not toward the back of the bobbin case.
I will let you know how this works. I HOPE to be happily sewing on my 830 with no thread problems, in peace and quiet tonight while DH and son are watching the Superbowl!