Microphone Circuit Between Microphone and Radio Receiver

AUDIO / VISUAL: AUDIO AND VISUAL SYSTEM: Microphone Circuit between Microphone and Radio Receiver
- Microphone Circuit between Microphone and Radio Receiver

DESCRIPTION

This circuit sends a microphone signal from the telephone microphone assembly to the radio receiver assembly.

It also supplies power from the radio receiver assembly to the telephone microphone assembly.

WIRING DIAGRAM

INSPECTION PROCEDURE

PROCEDURE

1. CHECK RADIO RECEIVER ASSEMBLY

(a) Disconnect the K25 radio receiver assembly connector.

(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Result

C -- REPLACE RADIO RECEIVER ASSEMBLY Removal

B -- REPLACE RADIO RECEIVER ASSEMBLY Removal
A -- Continue to next step.

2. CHECK HARNESS AND CONNECTOR (RADIO RECEIVER - ROOF CONSOLE BOX)

(a) Disconnect the K25 radio receiver assembly connector.

(b) Disconnect the W7 roof console box assembly connector.

(c) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

3. REPLACE TELEPHONE MICROPHONE WITH ANOTHER AND CHECK

(a) Replace the telephone microphone assembly with a normal one Removal.

(b) Check if the same problem occurs again.

OK:

Malfunction disappears.

Result

C -- REPLACE ROOF CONSOLE BOX ASSEMBLY Removal

B -- REPLACE ROOF CONSOLE BOX ASSEMBLY Removal

A -- END (TELEPHONE MICROPHONE IS FAULTY)