Precor 9.31 Manual page 25

3. Measure the voltage between terminal 1 of J3 and terminal 4 of J3 on the lower PCA, see
Diagram 5.2. The voltage should read approximately 5 Vdc. If the voltage is missing or
significantly low, disconnect the speed sensor plug from the lower PCA. Measure the
voltage between pins 1 & 4 of the J3 connector on the lower PCA. If the voltage is
approximately 5 Vdc, replace the speed sensor. If the voltage is missing or significantly low,
replace the lower logic PCA.
4. If at this point the speed sensor output is good, but a speed error occurs, replace the upper
PCA.
5. If you have performed all of the above procedures and have been unable to correct the
problem, call Precor Customer Support.
9.31, 9.33, 9.35 Treadmill
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