chris is right, never replace a power card in a duplex system without shutting down both cars, It is in the manual, and i have personally experienced what happens if you don't follow this advice. turn both cars off, remove power card you want to replace, install new card, and turn on, adjust 5 volts as Q says, i use a little wooden stick to adjust the pot, adjust for 5 volts. the other pot is the motor limit timer pot, I usually just turn it to its max setting, you will know which way is correct, cause it will shut down on low oil timer if you turn it the wrong way. thats about it.
