There will be several small capacitors on any control board but I guess you mean the motor's Start/Run capacitor...
These things are usually quite large - the one in my Bosch washer is an aluminium cylinder about 35mm diameter and 90mm long with several push on connectors at one end and a mounting bolt on the other end - to attach it to a bulkhead.
Your capacitor may be slightly different in size, shape and mounting style but it should be easy to spot. There will probably be printing on it - mine says 0.5uF + 2x 0.02uF + 2x 1mH +680k Ohms
In the can (on my machine) are..
One 0.5 microfarad capacitor
Two 0.02 micrrofarad caps
Two 1 milli Henry chokes
One 680K resistor
Check on Google - Images - enter start run capacitor to see pictures of the various styles.
Capacitors can sometimes give you a shock even with the machine unplugged - take care...
Good luck...
Peccavi
November 2009