Sharp GX20 Service Manual - Page 50

GX20 2. Incoming audio cannot be heard. Phone CONFIDENTIAL Signal output at the Back light FPC earpiece contact terminal? YES Built-in earpiece defective or defective connection between TP167 and TP168. NO Signal output at CN402 1 pin and 2 pin? YES Back light FPC or CN402 defective. Or defective connection between Back light FPC and CN402. NO Signal output at TP167/TP168? YES Defective connection between L103 to CN402 1 pin or L104 to CN402 2 pin. NO Signal output at C102? YES L103 or L104 defective. NO Signal output at both ends of C120? NO Voltage of more than 0.5 V applied to C186 (IC102 6 pin side) ? NO Voltage of more than 0.5 V applied to JK301 5 pin? NO Voltage of more than 0.5 V applied to JK301 3 pin? YES Defective parts of L103 to IC102 62 pin and L104 to IC102 61 pin. YES IC102 or PWB defective. YES Parts of hands free connector JK301 5 pin to IC102 6 pin defective or connection of Relay FPC-B with CN306 and CN202 defective. YES Hands free connector JK301 defective. NO Voltage of more than 0.5 V applied to TP106? NO Voltage of more than 2.4 V applied to Q101 3 pin? YES Parts of hands free connector JK301 3 pin to TP106 defective or connection of Relay FPC_B with CN306 and CN202 defec- tive. YES Parts of Q101 3 pin to TP106 defective. NO Voltage of 3 V applied to Q101 2 pin? YES Q101 defective. NO IC104 defective. 2 - 44