Brother GTX-4 Service Manual page 360

Assembly
(1) Release the lock lever stopper of a new switch to be replaced.
(2) Shift the lock lever to the unlock position and separate the contact block from the switch operation unit.
(3) Remove the keytop and diffuser.
(4) Remove the lock nut and check the presence of the rubber washer.
Lock lever stopper
(5) After putting the rubber washer through the switch operation unit, attach the unit on the start switch plate.
(6) With the TOP mark of the operation unit placed toward the front, tighten the lock nut.
Rubber washer
Operation unit
(7) Loosen the terminal screws of the contact block and connect the yellow and red wires of the print switch harness to
its lamp side.
(8) Reverse the contact block and connect the brown and black wires to its switch side.
Yellow wire Red wire
Lamp side
Disassembly / Replacement / Adjustment
Rubber washer
TOP mark
Brown wire
Switch side
6-169
Operation unit
Black wire