008 Sears CA Treadmill Service Manual [rev 1.0] |
7
Section Three |
Troubleshooting
Treadmill Troubleshooting
>>
Erratic Speed | Running Belt | Model 30750 Only
Symptom
Possible Cause
Test Procedure
Repair
Belt overshoots desired
speed on console and
then slow back down.
This can happen
during operation or
when you first press
start.
-Speed of the belt will
not match the displayed
speed.
Failed speed sensor or
console cable.
-Check to see if the
speed sensor is properly
connected to the lower
board.
-Check position of
sensor (Wire coming
from sensor points
towards the front of the
machine, is a close to
the front roller as
possible without
touching, and the
sensor bracket is at a
90- degree angle, not
bent in any way).
-Verify there is a magnet
in the front roller.
-Check console cable for
pinches and make sure
it is connected properly
to both the upper and
lower boards.
Send speed sensor and
console cable. Replace
parts as needed.
Running belt feels
choppy, almost like it’s
stuttering when a cus-
tomer walks
-Torque adjustment on
lower board is incorrect.
-Running belt is loose.
-Tighten running belt.
(Do not overtighten belt
if it still feels choppy.)
-Tech in the field only:
Adjust torque pod until
belt runs smooth.
Replace lower board.
Running belt continues
to move even after stop
is pressed
-Torque Adjustment on
lower board is incorrect.
-Tech in field only:
Adjust torque pod until
belt stops.
Replace lower board.
Why this happens: If the speed sensor is defective then the belt will keep moving as it’s trying to get
that info. It will speed up a little as it realizes there is no signal from the speed sensor then slow down
to the default PWM value in the console. For the units without auto-cal there are some speeds that are
preset in the upper board to keep it running. It will try to use the speed sensor but if that is not working
it will use the pre-programmed values instead. It works kind of like auto cal but the values are already
programmed instead of set for each individual unit so they will not be as accurate.
