Do you think this is an electrical problem? Or simply a feature of the sewing machine? The only way a user's manual will help is if it is a feature of the machine, but this is not a feature I have heard of before.
There are very few free sewing machine manuals online. I couldn't find one for your model. I did find a manual on eBay for your machine, though:
http://cgi.ebay.com/ws/eBayISAPI.dll...m=250386514179
As others have mentioned, it would help to have a picture of the machine and a description of the button you have to push to get the needle to go up and down.