Originally Posted by GiGi
Please make sure your have the RIGHT SIZE bobbin. My bobbin was just a mm off and it that caused my machine to do the bird's nest. I know how this sets one back. Very aggravating isn't it? :D
Yes, in addition to each of the other tips and ideas, I was going to ask if you might be using a bobbin that goes to a different machine. Having had several machines, inheriting stash, and such I have bobbins out the yingyang. Brother is bad about making their machine sensitive to a foreign bobbin and they don't use the same bobbin for each machine in their line.
For the cleaning, I am blessed to have a husband that knows how to disassemble a machine, clean/oil and put it back together. All the lint and critters have to come out eventually.
Good luck, please let us know what you think the solution was.