Figure 2-60. Removal of printed circuit board.

TM 5-6675-250-34

Table 2-1. Troubleshooting - Continued

MALFUNCTION

TEST OR INSPECTION

CORRECTIVE ACTION

CAUTION

TS 006299

Figure 2-60. Removal of printed circuit board.

b. Unfasten ten screws securing the printed circuit board to the mounting bracket and loosen the board to obtain access to

electrical connectors.

CAUTION

To avoid damage to the electrical connectors, alternately back-off each of the two attaching screws when removing the

connectors.

c. Disconnect two electrical connectors (2A2J5 and 2A2J6) by unfastening two screws at each connector.

Remove printed circuit board.

d. Depress and hold RESET switch and using an. ohmmeter, check continuity between pins 1 and 2 of switch (2A2S5).

If continuity is not present, replace RESET switch (2A2S5).

(1). Remove parts attaching the switch to the electronic control panel assembly.

(2). Unsolder the electrical leads from the bad switch and tag the electrical leads for identification.

(3). Install a good switch in the electronic control panel assembly and secure with attaching parts.

(4). Connect and solder the electrical leads in accordance with the identification tags.

CAUTION

To avoid damaging the electrical connectors, alternate tightening each of the two screws during reassembly.

(5). Install printed circuit board, but do not tighten mounting screws. Connect the two electrical

connectors and secure by tightening two screws. Fasten ten screws that secure printed circuit

board to mounting brackets.

(6). Install electronic control panel assembly in case and secure with eight captive screws.

Step 2. Inspect printed circuit board for evidence of damage or failed components.

a. Loosen the eight captive screws and lift the electronic control panel assembly from the case (Figure 2-60).

b. Unfasten ten screws securing the printed circuit board to the mounting brackets and loosen the board to obtain access to

electrical connectors.

CAUTION

To avoid damage to the electrical connectors, alternately back-off each of the two attaching screws when removing the

connectors.

c. Disconnect two electrical connectors (2A2J5 and 2A2J6) by unfastening two screws at each connector.

Remove printed circuit board.

d. Inspect printed circuit board for visual evidence of cracked circuits, corrosion, bums or

other evidence of defects.

Replace a bad printed circuit board.

CAUTION

To avoid damaging the electrical connectors, alternate tightening each of the two screws during reassembly.

(1). Install a good printed circuit board, but do not tighten mounting screws. Connect the two

electrical connectors and secure by tightening two screws. Fasten ten screws that secure printed

circuit board to mounting brackets.

2-50,

Change 1