Procedure 5.2 - Troubleshooting The Lift System - Precor 9.31 Manual

Procedure 5.2 - Troubleshooting the Lift System

Lift System Description:
The lift system on these units consists of an A.C. line voltage driven lift motor (120 Vac), and an
internal 1 KΩ potentiometer for lift position identification. The lift motor contains two motor
windings, one to operate the motor in an "upward" direction and the other to operate the motor in
a "downward" direction. As the lift motor is operated, the motor also rotates the potentiometer via
an internal gear system. Therefore, the position of the lift system can be determined by
monitoring the value of the internal potentiometer. The lift motor is initially set at a known starting
position (calibration, See Procedure 4.1), subsequent motor movement is tracked via the
potentiometer resistance reading. Note: If the potentiometer circuit is shorted the diagnostics
A/D number will be 0, if the potentiometer circuit is open the diagnostics A/D number will be 255.
Note:
All resistance measurements must be performed with power removed from the treadmill.
Performing resistance measurements with voltage applied may damage your ohmmeter.
Procedure
1. If the lift motor operates but creates a lift error (error 40 or 42) go to step 16. If the lift motor
will not move continue with step 2.
2. Set the treadmill's circuit breaker in the "off" position and remove the A.C. line cord from the
A.C. outlet. Remove the treadmill's motor cover.
3. Remove the F1 (Lift) fuse from the lower PCA. Using an ohmmeter, check the resistance of
the F1 fuse. See Diagram 5.2. The fuse should measure approximately 0.1 Ω or less. If the
fuse is open or high resistance, replace the fuse.
Diagram 5.2 - Lower PCA
F1 (Lift) Fuse
J1
A.C. Input Wires
9.31, 9.33, 9.35 Treadmill
J3
J4
J8
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