I have a New Balance 1500 Treadmill which I love and it has worked great for the past 6 or 7 years. Now when I tried to put it into mountain path it stopped and an E1 showed on the screen. I turned the machine off and unplugged it for a few minutes, but when I started it again in just a regular timing mode it showed E1 again and did nothing. Help!! What does E1 mean, I can't find my owners manual.