I have a Max Trainer M7 and was using it for a few months on the 14 and even a 21 minute workout 3 times a week. I got on about two months ago and as soon as I scrolled through the menu to set my workout and as soon as it engaged the resistance would rise to the point I could almost stand on the steps without it moving and I weigh 275lbs. Watched a few videos and took the machine apart and found no problem with the cables. Looking for suggestions! I have a warranty left. Help!