Are you using 100% cotton instead of fleece or flannel to work on until you get everything up and running?
A couple of searches turned up
Heating up the inside (how about that dryer or over a heating vent.
Check to see if a belt is twisted.
Motor polarity reversed (don't know anything about this!)
ETA:
http://www.quiltingboard.com/t-35070-1.htm
She has the same machine - maybe she's had similar problems.
ETA: don't know about this downloadable site but may be worth a try.
http://free-tutorial-for.me/search/t...hine-mod-2468/
ETA: found this info:
Feed Dogs The feed dogs are located beneath the needle and presser foot and move forward or backward to feed your fabric through the machine smoothly and evenly. Occasionally the feed dogs can get stuck in a reverse-feed direction and, no matter what setting you have your machine on, will only run backwards.
Reverse Lever The reverse lever on a sewing machine is most often a push-button or mechanical lever that you push when you want your fabric to feed in reverse. This button occasionally gets stuck or broken internally in the reverse position, causing the machine to only run in reverse.
ETA: Another site:
To all the people with this problem. What has happened is the reverse mechanism has stuck, this is often due to not being used for a while or the machine has not been oiled properly, which is hard to do for a user as you virtually have to remove all the covers.
If this particular machine has a screw on cover at the end where the handwheel is, remove it and look inside, you will see the mechanism, what you need to do is push it back out, then oil it but make sure you work the reverse button in and out while you oil it and check it works freely, then just refit the end cover.
Ok I'm done - but can't wait to hear you've figured it out!