Look for a damaged gear under the machine, remove the bottom cover and look for a plastic gear that may have split or cracked. You may see a brocken gear tooth in the base on the machine. Look at the gears on the shafts while rotating the machine mechanism by turning the hand wheel - These sewing machine gears are very reasonably priced and can be replaced as a DIY job.
After these DIY project/repairs you will need to re-time the sewing machine. You can find details on how to retime a sewing machine in this section.
Replace gear - Re-time machine
The hook timing out, needle will not pick thread up - Re-time machine.
Timing belt jumped a tooth - Re-time machine