NordicTrack skiers provide a workout similar to cross-country skiing. The NordicTrack "skis" slide back and forth on a stationary track, getting resistance from the flywheel and connected resistance strap. Arm cords attached to handles and running through a pulley system at the front of the machine let you work your arms, too. These manual machines do not have a lot of parts, but malfunctions with the machine typically can be troubleshooted.
Check the console wire if the display is dim. Push the wire firmly into the jack on the bottom of the console and into the jack on the upright. The console wire must be inserted completely into both jacks for the console to show correct feedback. Change the batteries if the wires are not the problem by removing the battery door or cover, taking out the old batteries and putting new batteries in the compartment with the positive and negative sides in the same orientation as the old batteries.
Untangle the arm cord if the "A" and "B" sides have become twisted. Consult your manual if you do not remember which side is which from when you assembled the machine as the sides are not marked. Detach the handgrips first to get to the cords. Untie the knot and remove the washer inside the handgrips. Pull the arm cord out of the small pulley and unwind it, taking care to remember how it is set up. Wrap the "A" cord counterclockwise around the pulley until there is no more of the arm cord to wind. The "A" cord is simply one side of the arm cord. Pass the end of cord "A" through the right small pulley. Wrap cord B, the other side of the arm cord, around the pulley. Feed the end of cord "B" through the right small pulley from right to left. Continue to pull the "B" cord until it is the same length as cord "A." Pull each side gently to smooth out the arm cord on both sides. Replace the handgrip in the same manner it was removed.
Check that all the parts of the arm cord assembly are installed if it is making a screeching noise. Use 100-grit pad of sandpaper to roughen the surface of the resistance pad. Place a drop or two of light household oil on to the leather resistance pad and spread it evenly. Put oil on the washers if the noise still has not stopped.
Use a clean, dry cloth to remove excess oil from the skis if they are slipping. Place a small amount of paint thinner on a dry cloth and clean the bottom side of the skis.
Remove the "U" bolt cover from the flywheel, which is the large wheel at the back of the skier in between the ski rails. This may involve simply sliding the cover to the right, depending on your model. See your manual if you need help. Use the flat wrench tool that came with the skier to tighten the flywheel nuts. Tighten each bolt evenly. This should help if the skis are slipping or if you are not getting resistance from the flywheel or resistance traps.