Pat,
I'm so sorry for your troubles. I don't own a Tin Lizzy but I'd like to recommend you join the Yahoo group.
(they won't let me post a link for some reason but you can find it through a Yahoo group search)
You will find a wealth of information about the issues your machine is having.There might even be someone who can give you some advice about what the real underlying problem with your machine is. These people have seen it all! I joined a group for Janomes and I've gotten lots of help from other 6600 owners. Good luck!