I used my serger for about 30 minutes after not using for about 2 years, and it started to smell a bit like motor burning, and then stopped working. I unplugged it, rethreaded it, looked to see if there was a thread jam and everything looks okay but when I push on the foot pedal nothing happens......but the light does come on, so the electrical part is okay I think. Any help would be greatly appreciated, thanks!