PAT DS 150, Service Manual

Page: 38 / 55

Troubleshooting Flow Charts 31
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Measure supply to length transducer in cable reel at terminal between Pin 1 (ground)
and Pin 3 (-5v)
Refer to system wiring diagram.
Correct? No
Faulty wiring between central unit and
length transducer. Check wiring.
Yes
Measure signal from length transducer in cable reel between pin 2(signal) and pin 1(ground).
Retracted boom, with no turns on the potentiometer, signal is -0.500v
At 10 turns on the potentiometer the signal measurement would be -4.500v.
Therefore the voltage of an extended boom will be between -0.500 to -4.500 volts .
Correct? No
Replace length potentiometer assembly. Remove slip ring body from shaft and
remove gear wheel from potentiometer axle. Unscrew mounting plate a nd
remove potentiometer assembly from mounting plate. Remove assembly wires
form terminal block. Connect new assembly to terminal block. Reinstall
mounting plate, gear wheel and slip rings. With boom fully retracted, reset
Yes
Measure signal from length transducer in central unit main board between X1:8 (ground) and X1:10
(signal: -0.5 and -4.5v) Refer to system wiring diagram.
Correct?
Faulty wiring between central unit and length
No
transducer. Check wiring.
Yes
Continued from previous page.