2.
No Resistance and No Field Light
•
Begin moving the staircase.
•
Staircase freewheels and field LED does
not light.
•
Perform tach test by entering
diagnostics.
•
If there is no tach signal sensed on
console.
o
Check for .6 to .7 volts AC at the
W-4 (Tach) terminal of the
alternator.
o
If no voltage, remove the blue
tach wire from the alternator,
while staircase is moving.
Touch the tach wire to
the field terminal.
If the field LED lights,
replace the alternator.
o
If the voltage checks good,
remove the blue connector
from the W-4 (Tach) terminal of
the alternator. Lightly scrape
the connector and re-install.
Re-check.
•
If still bad, replace the console.
3. Staircase has resistance but is choppy during exercise.
• Inspect Main Cable for Corrosion at all connections.
• Check Load Resistor for a reading of .5 to.6 Ohms. If lower than .5 ohms, then replace the load resistor (SM24989).
• If
load resistor checks good, replace the alternator brushes (SM24557) or alternator (SM22900).
Last revised 10/5/15
