The motor runs on my Euro-Pro 416. I can wind a bobbin. I can move the needle downward manually but when I press the pedal the motor runs. The needle doesn't move. What is wrong?

SOURCE: needle will not pick up bobbin threat

I had the exact same problem. The timing is off. You can actually fix this yourself all you need is an allen wrench. If you look at the rod the needle is inserted into and follow it up to about 2 inches below the top of the machine there should be a clamp. use the allan wrench to loosen the clamp and adjust the needle height. I used this website as a guide to getting the timing correct. http://www.sewusa.com/Sewing_Machine_Repair/Repair_Pictures/timing1.gif

now if only I could figure out why my thread keeps getting jammed under the bobbin!

SOURCE: thread jams & wheel axel cannot turn

there are a couple of things that come to mind.  
Bobbin:   wound with uneven tension.  Try taking the bobbin, rewind that thread onto another bobbin and wind slowly.  make sure the thread feeds onto the new bobbin evenly.
upper thread:  catching on something or not flowing off the spool easily.
you're doing well, sounds like you consulted the manual and used your noggin, hang in there and let me know if this doesn't help.  we can troubleshoot some more!

SOURCE: can't wind bobbin kenmore 16221 sewing machine, no manual

On the right side of the machine there is a large knob at the top. Pull that out and you can wind your bobbin. Don't forget to push it back in so you can sew :)

SOURCE: Kenmore 158.1703 sewing machine - needle not going up and down

The machine sounds like it has threads caught in the bobbin area thus locking the machine up. Check in there and maybe you can pick them out with tweezers. They may need to be 'softened up' with a little oil before you can get them out!. also Please push the bobbin winder back to the left position and it will release the bobbin winder. Then you should be able to sew. If the needle won't move, you will need to tighten the turning wheel on the right side end of the machine. This should move your needle. Then you should be set to sew.
------This will help. Thanks please keep updated.please do rate the solution positively .thank you for using fixya

SOURCE: Tiny Tailor bobbin won't wind

I don't know the solution but you can find the manual here:
http://www.singerco.com/accessories/manuals.html

Do search for TT600 when given the model number (do NOT use TT600X since it wll say not found). It's a very nice manual that is in PDF format.