Procedure 6.1 - Display Does Not Illuminate - Precor RBK 815 Service Manual

Procedure 6.1 - Display does not Illuminate

Note:
In order to conserve battery power when the cycle is not in use, a time out feature is
incorporated in the cycles software. If the cycle is not used (motion not detected by
the speed sensor), when in the program mode, approximately 15 seconds later, the
cycle will "power down" The bike will "power up" again when pedaling is resumed
(motion detected by the speed sensor). In order to measure voltages in the unit it is
necessary to keep the unit powered up. This can be accomplished either by pedaling
on the unit or by installing the optional external power adapter.
1. Attach the anti-static wrist strap to your arm, then connect the ground wire of the
wrist strap to the units frame.
2. Pedal on the cycle for a minimum of 5 seconds. The system monitors one of the
three phase generator windings for AC zero cross. The monitoring system notes
every time the generator AC voltage passes through zero volts. By counting the
zero cross rate, the system knows how fast the generator is turning. The system
calculates the user RPM from the generator speed. If the system does not see a
zero cross rate, it assumes the bike is not being used and the display will not
illuminate when the bike is pedaled.
3. Disconnect the generator leads from terminals M3 (red) and M4 (black) on the
lower PCA. Connect and AC voltmeter to the leads removed from terminals M3
and M4. Pedal the bike at about 60 RPM (1 rotation per second), the voltmeter
should read approximately 120 Vac. If the voltage reading is absent or extremely
low, replace the generator.
4. If the voltage reading in step 3 was normal, replace the lower PCA. If the lower
PCA did not correct the problem, continue with step 5.
5. With the unit powered up, measure between test point 19 and test point 20 for
approximately 8.5 Vdc. See Diagram 6.1. If the measurement is correct, skip to
step 7.
RBK 815 Recumbent Cycle
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