please help me fix my Horizon paragon 2?

motor does not turn belt.When start is activated I get a click noise from the lower board.I have as far as I can see checked the electrical connections for looseness, under the bottom cover and also in the control panel.I have cleaned the dust off what I believe to be a magnetic sensor on the pulley wheel and I have also moved the belt with my foot and pressed the start button with no result.Has anyone got any idea's or can someone help please.I am in Nottingham.Kind regards