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W450769A 01/14
3.4 “No Fault Code” Problems
This section addresses problems not reported by the computer fault code system.
3.4.1 Anti-Two-Block Alarm (ATB)
This section gives direction to fault diagnosis of ATB alarm problems. For detailed information,
schematic, and voltages, refer to
SECTION 3.9 - ANTI-TWO-BLOCK FUNCTION OVERVIEW
.
PROBLEM:
•
The Anti-Two-Block alarm is continuously ON. Operating the switch at the boom head does not
deactivate the alarm.
•
This problem suggests an open circuit between the computer ATB input and the ATB
switch(es), or an open circuit between the computer ATB feed and the ATB switch(es).
•
Check the Reeling Drum cable for damage.
•
Ensure the Two-Block switches are correctly connected.
•
Check the slip-ring and wiring inside the Reeling Drum.
•
Check the signal cable from the Reeling Drum to the computer.
•
Check the connectors.
PROBLEM:
•
The Anti-Two-Block alarm is continuously OFF (safe). Operating the switch at the boom head, by
lifting the ATB weight does not activate the alarm.
•
This problem suggests a short circuit between the computer ATB input and the computer
ATB feed somewhere between the computer and the ATB switch(es).
•
Check the Reeling Drum cable for damage.
•
Ensure the Two-Block switches are correctly connected.
•
Check the slip-ring and wiring inside the Reeling Drum.
•
Check the signal cable from the reel to the computer.
•
Check the connectors.
