MAINTENANCE NOTICE
June, 1998 MN-98-002
DIGITAIR® SBU Model 6695
Ribbon Cable Assembly (N24610001)
Introduction
A limited number of SBU Model 6695 units were
shipped with a potentially defective ribbon cable
assembly (PN N24610001). This cable assembly
connects the EOT Motion Sensor Unit (PN
N24610101) to the main SBU PCB. It has been
determined that occasionally these assemblies
“short out” during operation.
Corrective Action
US&S has determined that the problem is
attributed to faulty connection between the ribbon
cable and pin connectors. Replacement of the
ribbon cable assembly will solve this problem. All
replacement ribbon cable assemblies have a
yellow dot on the side of one of the pin
connectors.
To replace the ribbon cable assembly, use the
following procedure:
1. Take the SBU out of service and disconnect
power to the unit.
2. Remove the back panel from the SBU.
3. Remove the existing ribbon cable assembly
(see Fig 1 and 2) and discard.
4. Install the replacement ribbon cable assembly,
as follows (see Fig 2):
a. Connect the pin connector to the motion
sensor. This connector is keyed and cannot
be installed incorrectly. The red strip on the
ribbon cable will be toward the top of the unit.
b. Connect the opposite end of the cable to the
motion detector pins on the main PCB. The
red strip must remain up and the cable must
not be twisted.
5. Replace the back cover, applying 12 in-lbs. of
torque to the screws.
End of ribbon cable replacement procedure
Fig 1. Top of SBU
Fig 2. Detail View
For additional information about End-of-Train
equipment or ordering parts, contact US&S
Customer Service at 1-800-652-7276.
Technical questions or information regarding the
contents of this Maintenance Notice should be
directed to the
R.A.I.L. Team via telephone at
1-800-652-7276 or via Internet e-mail at:
railteam@switch.com.
Ribbon Cable
Assembly
Main PCB
Motion Sensor Unit
Ribbon
Cable
Assembly
