White sewing machine LS-2125 problems

I want to thank R A Ellis for the effort, but it didn't work. I did everything suggested, changed bobbins, changed needle old one had red top and I think those are Singer/Slant needles including changing thread colors to diagnose the problem further and re-threaded a million times. Here are my further observations: When sewing without fabric or upper thread through needle, sews great. As soon as it's threaded, it jams when trying to sew. When I start to sew, it immediately locks up. The balance wheel takes effort to turn. You can keep turning it, but it sounds like it's breaking threads. If I sew with the bobbin door open, it doesn't look as if the top thread is going around the bobbin part and just goes back the way it began. When I tried to pull the top thread out to re-thread, it seemed to be stuck somewhere near the Upper Tension Control Dial. The inside doesn't look dusty or dirty. This is the last chance for this cute machine. Bought second hand and was going to give it to a young woman who needed it. Oh well.