There will be several capacitors in your machine - a mobile 'phone for instance has hundreds of them in it but really small ones...Your exercise machine will have several of them on any printed circuit board and one or two in any DC power supply - the ones you may be talking about are possibly Motor Run and or Motor Start capacitors. These capacitors are usually quite big - often silver in colour (color) but not always and often cylindrical in shape but not always.
Go to Google - select Images - enter motor start capacitor for thousands of pictures.
Peccavi
August 2009