Resistance stuck at a high level

I have a Golds Gym Stride Trainer 350i and have owned it for 6 months, the past 3 of which I haven't used it. I tired to use it and it seems the resistance is stuck on a very high level making it almost impossible to use for a long amount of time. I've tried shifting up and down on the resistance, but nothing seems to help. I've looked inside and nothing looks like it is rubbing. Tension motor makes a humming noise when close to it, but that might just be because I've never been down that close to hear it before. Help!