how may i fix a circuit bord? for a RBK edge 2.2 treadill, and ,or I-RUN?

Your consumer unit trip will be a function of mains electricity - circuit boards often operate on low voltage DC power - however - the circuit board may have components on it that take the incoming AC - transform it to a lower voltage - rectify it and subsequently regulate it to the DC voltage needed. There may also be components that deliver pulsed mains voltages to the motor.

Pay attention to any components that "take" mains power - Transforming - Rectifying - Motor control. The motor may be driven by a largish transistor-like device often mounted on a heat sink - this may be the culprit.

I know nothing of exercise equipment and my knowledge of electronics is somewhat out of date.

You might be able to fix it yourself but you will need some basic knowledge and the appropriate tools - soldering iron, multimeter etc.

Good luck...

Peccavi
June 2011