Table 2-3. Troubleshooting, Remote Control Unit.

TM 11-5820-477-30

Table 2-3. Troubleshooting, Remote Control Unit.

Malfunction

Test or Inspection

Corrective Action

1. NO RINGER SIGNAL OUTPUT.

Step 1. Check magneto G201 for output voltage.

If output is inadequate, replace magneto (paragraph 2-9).

Step 2. Check capacitor C214.

If defective, replace (paragraph 2-13).

Step 3. Check audio line transformer T201 by checking winding resistance between terminals 5 and

6 of transformer (paragraph 2-5).

If defective, replace (paragraph 2-13).

Step 4. Check for proper mechanical functioning and continuity of microswitch S203.

If defective, replace (paragraph 2-13).

2. BUZZER IS NOT ACTIVATED WHEN RINGER BUTTON ON LOCAL CONTROL UNIT IS PRESSED.

Step 1. Check capacitor C214.

If defective, replace (paragraph 2-13).

Step 2. Check for proper mechanical functioning and continuity of microswitch S203.

If defective, replace (paragraph 2-13).

3. CALL LAMP DOES NOT LIGHT WHEN RINGER BUTTON ON LOCAL CONTROL UNIT IS PRESSED

(A -, B- AND C- MODELS ONLY).

Step 1. Check for defective lamp.

If defective, replace (paragraph 2-14).

Step 2. Check for defective call lamp control relay by checking relay windings out of the circuit.

Resistance between terminals 1 and 2 should be 5,000 ohms; resistance between terminals 3

and 4, should be infinite.

If defective, replace (paragraph 2-12).

NOTE

In A-, B- and C- models, ringing signals are applied through an RF filter assembly.

Check the continuity of the RF filter (figures FO-2 through FO-4) if the call lamp or the

buzzer of either control unit is not activated.

Step 3. Check for defective buzzer DS201.

If defective, replace (paragraph 2-11).

2-9