OK, I was able to get into the top and I see nothing broken. Gears all look fine. Opened the bottom and it looks just like your picture. Timing belt intact. I'll try to attach a pix of the area I think is the problem. See the arrow? Nothing in that area moved when I use the hand wheel to raise and lower the needle. It is not disengaged for bobbin winding. On my other machines something in this area moves to make a loop for the needle thread. And the instruction book shows it threading from front to back.