NAVELEX EE 181-AA-OMI-120/E121 C-7359-60-1
REPAIR OF SIGNAL MODULE
6-1. REPAIR OF SIGNAL MODULE. Repair of the Signal Module is restricted to removal and replacement of the
audible signal device and the logic subassembly printed circuit board.
To remove the audible signal device, unlock and open the Monitor Cabinet door. Unlatch and swing out the
mounting rack. Tag wires, unscrew terminal screws, and disconnect wires from audible signal device.
Unscrew knurled nut and slide audible signal device from Signal Module.
To install new audible signal device, position audible signal device in Signal Module. Screw knurled nut on
signal device. Connect wires to terminals and install terminal screws. Close and latch mounting rack. Close
and lock Monitor Cabinet door.
To remove the logic subassembly printed wiring board, unlock and open the Monitor Cabinet door. Unlatch
and swing out the mounting rack. Tag and remove wires from terminal board TB1 located on back of signal
module. Remove the screws holding it in the rack and pull the module out of the rack. Place signal module
on the bench. Remove four screws and lock washers from the signal module cover and remove the signal
module cover. Tag wires and use a soldering iron of 50 watts maximum to disconnect wires from logic
subassembly PC board. Remove mounting screws and lock washers. Remove logic subassembly PC board
from Signal Module.
To install new logic subassembly PC board, position board in Signal Module and install mounting screws and
lock washers. Use a soldering iron of 50 watts maximum to solder wires to printed wiring board. Position
Signal Module cover and install screws and lock washers. Position Signal Module in mounting rack and install
mounting screws. Connect wires to terminal board TB1. Close and latch mounting rack. Close and lock
Monitor Cabinet door.
6-2. CHECKOUT PROCEDURE.
After repair, test Signal Module for proper operation.
Interrupt ac power by removing fuse F2 from Monitor Control power supply. Module lamps should be flashing
and audible signal should sound. Momentarily depress ACKNOWLEDGE switch. The lamps should be
extinguished and the audible signal should be silenced. Restore ac power by reinstalling fuse F2 in Monitor
Control Power Supply. Signal Module lamps should be flashing and audible signal should sound.
Momentarily depress ACKNOWLEDGE switch. The lamps should be on-steady and the audible signal device
should be silenced.