SHARP TQ-GX20A
Service Manual

GX20
Hands free kit (Headset) When replacing the hands free kit, output avilable?
NO

CONFIDENTIAL
YES

Hands free kit defective.

Voltage of 1 to 1.9 V applied to JK301 3 pin?
NO

YES

E

Voltage of 1 to 1.9 V applied to TP106?
NO

YES

Parts of L105 to JK301 3 pin defective.

Voltage of more than 2.4 V applied to Q101 3 pin?
NO

YES

Parts of Q101 3 pin to L105 defective.

YES

Q101 defective.

Voltage of 3 V applied to Q101 2 pin?
NO

IC104 defective.

G E

Voltage of approx. 1 V applied to IC102 44 pin?
NO

YES

F

Voltage of approx. 1 V applied to IC102 40 pin?
NO

YES

IC102 defective.

Voltage of more than 2.4 V applied to Q101 3 pin?
YES

NO

G

Parts of R107, R108, C113 and L106 defective or soldering defective.

F

Voltage of 0 V applied to C186 (IC102 6 pin side)?
NO

YES

IC102 defective or soldering around C186 and R184 defective.

JK301 defective or R184 defective.

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