Precor TRM10/GEN06 Service Manual page 60

3 If this happens the lift will move (either up or down) as soon as
the unit is powered up. The typical result is that the lift will be
physically jammed as described above, and it will also probably
cause the lift fuse to blow. If the lift moves un-commanded as soon
as the power is turned on to the machine and eventually jams, the
lower control module (IFT drive) must be replaced. The lift switch
may also fail in an open condition. If this happens the lift will
not operate in one direction. Perform the following steps to
determine if the switch is open.

With the incline below 15% (to allow room for lift travel up),
connect an AC voltmeter between terminals 1 (white) & 6 (red) of
the INCLINE connector. (See Figure above for connector location,
and Figure below for the connector pin-out). Set the treadmill in
the manual program and press the INCLINE  key. The AC voltmeter
should read AC line voltage (either 120VAC or 240VAC). Note that
the AC line voltage reading will only be present before an error
condition is displayed. A correct reading here verifies that the
UP triac switch is working properly.
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