You might have a thread caught in the wheel. You would have to open the machine to see if you can find it.

Rescuer may be right...some machines allow you to just pull off the wheel. My Baby Lock does this and I once wound yards and yards of metallic thread that got caught in the wheel...I called my dealer and he said just pull the wheel off and remove any thread that got caught. BUT, I also had a problem when my machine wheel locked up for what appeared to be no reason at all...turned out that it did not get oiled properly at the factory and needed to be taken apart (by the dealer) and totally serviced with special attention to parts internally that needed a serious "drink" of oil. After this mishap, the dealer contacted Baby Lock and they agreed that it should not have happened and they gave me a new machine. Not sure when the last time your machine was serviced, but letting them sit for long periods of time might contribute to this kind of problem...not sure how old your machine is either.....

Sounds like something is stuck somewhere. I didn't use one of my machines for over a year when we were moving and settling. My dealer said for the long term health of my machine that while it might appear to be OK it was worth having it serviced so they could check out bits I couldn't. While I live three hours from my dealer he is always at the end of the phone and is happy to chat and give advice. Is this a option? I have spent a couple of hours with my friend following the dealers instructions very successfully. Also I would check the spool case holder area as I have had threads caught there that have to be removed. Have fun and do let us know how you get on.