Section III. GENERAL MAINTENANCE - TM-5-6350-264-14-P-40037

TM 5-6350-264-14&P-4

NAVELEX EE 181-AA-OMI-050/E121 DT546 M9442

TO 31S9-2FSS9-1-4

Section III. GENERAL MAINTENANCE

5-4. MAINTENANCE ACTION. The extent of direct

the Detector. On-site adjustment is made on the gain

control in the Detector and the sensitivity control in the

and general support maintenance is governed by the

Processor. Inspection only is made on the chassis.

Maintenance Allocation Chart (MAC), Appendix B. The

Periodic testing of the Vibration Sensor is not scheduled

MAC provides for on-site test and replacement of the

because the J-SIIDS is maintained in continuous

PC boards in both the Processor and Detector and the

operation.

vibration

pick-up

assembly

Section IV. REMOVAL AND REPLACEMENT OF MAJOR COMPONENTS AND ASSEMBLIES

5-5. REMOVAL AND INSTALLATION PRO-

Remove screws that secure assembly to

CEDURES.

mounting surface, and remove assembly.

To remove the Processor PC board, tag and

To install new pick-up assembly, orient

remove the wires from TB1 and TB2.

assembly so that red and black wires are

Remove screws holding the PC board in the

toward PC board. Tilt assembly so that edge

chassis. Remove the PC board. Note the

nearest PC board can be slipped under PC

position of sensitivity control for reference.

board. Insert assembly into chassis, flat

against mounting surface, and secure it with

To replace the processor PC board, orient

four screws.

the board so that terminal strips TB1 and TB2

are adjacent to the conduit connections.

After replacement of major components or

Secure the PC board to the chassis with

assemblies during troubleshooting, test the VS

screws. Attach the wires to TB1 and TB2.

for proper operation. Ensure that the key-

Adjust the sensitivity control on the new board

operated switch on the Control Unit is in the

to the same position as on the old board.

access position.

Remove the Processor

chassis cover and pull the TAS plunger all the

To remove Detector PC board, tag and

way out. Set multimeter to ohms and connect

disconnect wires from TB1. Disconnect red

leads to TB1-6 and TB1-2. The meter should

and black pick up assembly wires from PC

indicate 2, 000 ohms or less. Slowly open the

board. Remove screws that secure board to

cover on the first Detector. While the cover

chassis. Remove PC board. Note position of

flanges are still engaged, the meter indication

the gain control for reference.

should change to over 100,000 ohms.

Remove the cover. Pull the TAS plunger all

To install new Detector PC board, orient

the way out. The meter indication should

board so the terminal strip is adjacent to the

change to less than 2, 000 ohms. Replace the

conduit entrance hole. Secure the board to

cover. Repeat the test on the remaining

the chassis with screws. Connect wires to

Detectors. Use a straightedge across the

TB1, and connect red and black pick-up

Processor chassis to hold the TAS plunger

assembly wires to the marked terminals on

down. The meter should indicate 2, 000 ohms

the board. Adjust the gain control on the new

or less. Slowly raise the straightedge. After

board to the same position as on the old

the TAS plunger moves 1/4 inch (0.635 cm) or

board.

less, the meter indication should change to

over 100, 000 ohms. Disconnect the wire

To remove pick-up assembly, disconnect red and

from TB1-1. Set multimeter to ohms

black

wires

from

board.

5-22