Turn the computer on and let it boot in a MINIMAL fashion to DOS, Windows, or Linux. Cautiously, connect the controller to the game port while watching the monitor. If the screen goes blank, disconnect the controller immediately! This implies that there is a short circuit - a ground wire is touching a +5 volt wire. A very brief short should not damage anything and the computer should reboot. Open the case and recheck everything thoroughly. This condition must be corrected before the controller is connected again.
If everything seems normal when the controller is plugged in, test it with a standard joystick testing program, readily available off the Net for DOS, Windows, and Linux. If a speed adjustable game port card is installed, use the supplied utility program to set the card to a speed that gives the most throw with a good center trim. If there is a joystick calibration utility with the game port card, use it to determine if the controller works properly.
If the computer is running Windows 95, use the Joystick Calibration icon in the control panel. If none of these are available, the controller can be calibrated from within a game that shows the stick positions after calibrating, such as Flight Unlimited or MS Flight Simulator. Follow the utility's directions to set the trims for proper center, and confirm that there is a smooth response in each direction of each stick's axis. If a stick indicator moves in the opposite direction, then the pot is wired to the wrong solder post. The pot must be rewired before proceeding to the calibration step. If there is one direction of an axis that has better resolution than another, try turning the trim control for that axis in the bad direction and recalibrate. If flats of the shafts are too far out of position, it may be necessary to open the case and turn the whole pot. It may take some experimenting but a trim position can be found which will give a smooth response in both directions. The controller should be recalibrated after a change in trim since this changes the center position. Ensure that the sticks return to center and that there is no ``slop'' in the center, which would indicate a bad fit between the pot's shaft and the gimbal assembly. Enjoy your new controller!