SHARP TQ-GX5A
Service Manual

GX15
3. No voice is heard from the earpiece.
Phone (Handset) Do keypad tones and melodies sound?
YES

CONFIDENTIAL

NO

Go to the section �Earpiece (for loud speaker) does not work�. (see page 2-50)

Is 0.5 V or more applied to R101 (IC103 pin 9 side)?
NO

YES

IC103 is defective.

Is 0.5 V or more applied to JK101 pin 5?
NO

YES

Parts between socket JK101 pin 5 and IC103 pin 9 are defective.

Is 0.5 V or more applied to JK101 pin 3?
NO

YES

Socket JK101 is defective.

Is 0.5 V or more applied to TP120?
NO

YES

Parts between socket JK101 pin 3 and TP120 are defective.

Is 2.4 - 2.6 V applied to TP176?
NO

YES

R122 is defective.

Is 2.4 - 2.6 V applied to R115 (IC103 pin 76 side)?
NO

YES

R115 is defective. (Hands free kit mode is set.)

IC103 is defective. Hands free kit (Headset) Replace the hands free kit. Is sound produced?
NO

YES

The hands free kit is defective.

Is signal sent to JK101 pin 4?
NO

YES

Socket JK101 is defective, or the hands free kit is in a poor contact with the socket plug.

Is signal sent to TP121?
NO

YES

Parts between socket JK101 pin 4 and TP121 are defective.

Is signal sent to R124 (IC103 pin 60 side)?
NO

YES

Parts between IC103 pin 60 and TP120 are defective.

Disconnect the hands free kit. Is voice heard in phone mode?
YES

NO

IC103 or IC106 is defective.

Is the voltage 0 V on R101 (IC103 pin 9 side)?
NO

YES

IC103 is defective.

Socket JK101 is defective.

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