Stairmaster 4400 PT/CL, 4600 PT/CL, 4200 PT manual Mechanical Troubleshooting, Page

MECHANICAL TROUBLESHOOTING

If you hear a grinding or clicking noise, experience excessive vibration during exercise, or if the pedals are not functioning properly, you probably have a problem in the drive train. Attempt to isolate the problem area by performing the following tests in precisely the order listed below. Refer to the “Parts Re- moval and Replacement” section for all disassembly and assembly instruc- tions.

1.Unplug the machine and remove the bottom side covers.

!WARNING

TO REDUCE THE RISK OF INJURY, DO NOT OPERATE THE MACHINE

WHILE THE COVERS ARE REMOVED. DO NOT DEPRESS OR RAISE THE PEDALS WHILE ANYONE'S HANDS ARE INSIDE THE MACHINE.

2.Noise can be generated by a Poly-V or HTD belt that is either too tight or too loose. Check the condition and the tension of the belts. Re- place worn belts. Adjust the belt tension according to the instructions in the "Parts Removal and Replacement" section.

3.Remove the Poly-V belt and move the pedal arms. If the noise no longer exists, check the condition of the alternator. If the noise is still present, go to step #4.

•Disconnect the DC power cable if you have a 4600/4400/4200 PT or unplug the connector from position J4 on the power supply circuit board if you have a 4600/4400 CL. Spin the alternator pulley with your fingers. It should spin freely and remain spinning for at least two revolutions. If it does not, the alternator should be replaced.

•If the alternator does spin freely, check the alternator for noise, roughness, or the presence of an excessive amount of black powder inside the alternator or near the outside of the case. If any of these conditions exist, the brushes might be bad and the alternator should be replaced.

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