Precor C954 Serivce Manual page 22

Procedure 5.2 - Troubleshooting the Lift System
Lift System Description:
The lift system on these units consists of an AC line voltage driven lift motor (120 Vac or 240
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:
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 treadmills circuit breaker in the "off" position and remove the AC line cord from the
AC outlet.
3. Remove the F2 (Lift AC) fuse from the lower PCA. Using an ohmmeter, check the resistance
of the F2 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
Fan Wires
F3
Fan
Fuse
F2
Lift
Fuse
Page 1-22
1 & 2)
C954, C956 Treadmill
(version
"Up" LED
"Down" LED
J5, Term 1
F1
System
Fuse
Page 22