Precor 9.45 Service Manual page 29

Procedure 5.4 - Troubleshooting the Lift System, 9.45
System Description
The lift system is powered by a 120 Vac lift motor that uses two independent motors windings.
One motor winding operates the motor in an upward direction and the other motor winding
operates the motor in a downward direction. The motor contains a 10 KΩ potentiometer, driven
by the motor, that indicates lift position. AC power to operate the lift motor is provided by a pair of
triacs. One triac provides power to the "up" winding of the lift motor and the other triac provides
power to the "down" winding of the lift motor. The triacs are controlled either manually or by
software control from the upper PCA.
1. If the lift motor will not move skip to step 7. If the lift motor moves and an error occurs
continue with step 2.
2. Access the diagnostics program per Procedure 2.1 or 2.2 and proceed to the lift calibration
portion of the diagnostics program. If the lift calibration number is 0 or 255 skip to step 3.
Operate the lift, if the lift calibration number does not increment as the lift moves, skip to
step 3. If the calibration number increments as the lift moves, recalibrate the lift per
Procedure 4.2. If recalibration does not correct the problem, continue with step 3.
3. Set the treadmill circuit breaker in the "off" position. Using an ohmmeter, measure between
terminal 4 (brown wire) and terminal 6 (orange wire) of the P2 connector on the lower PCA.
The measurement should be approximately 10 KΩ. If the measurement is open (∞) or
significantly high or low, replace the lift motor.
4. Using an ohmmeter, measure between terminals 4 and 5 of P2 and measure between 5 and
6 of P2 on the lower PCA. The two measurements should total approximately 10 KΩ. If the
measurement is open (∞) or significantly high or low, replace the lift motor.
5. If you have performed all of the above tests and an error still occurs when the lift motor
operates, there are three parts that could cause the problem. There are not any good tests
to check these parts other than substituting a known good part. They are lower PCA, ribbon
cable and upper PCA. Replace only one part at a time. If the new part does not correct the
problem replace the original part.
6. If you have performed all of the above tests and the lift system is still not functioning, call
Precor Technical Support.
7. Set the treadmill circuit breaker in the "off" position. Remove the F2 (2 amp slow blow) fuse
from the lower PCA. Measure the fuse with an ohmmeter. The measurement should be 1Ω
or less. If the fuse is good, re-insert the fuse and skip to step 9. If the fuse is open (∞)or
significantly high, replace the fuse. Before operating the lift motor it is necessary to perform
a continuity test on the lift motor.
(2P & 3Y Units)
9.45, 9.45i Treadmill
Page 29