Sharp TM200 Service Manual page 34

2. VOICE TRANSMISSION/RECORDING IS IMPOSSIBLE.
Phone
Replace the microphone. Is the problem solved?
Is 1.2 - 2.1 V applied to both ends of C101?
Is approx. 1.7 V applied to IC103 pin 80?
Is 2.7 or more voltage applied to R192 (IC106 pin 89 side)?
Replace C126 or C133. Is the problem solved?
IC103 and IC106 are defective.
Hands free kit (headset)
(The following procedure applies to both monaural and stereo headsets.)
Replace the hands free kit. Is the signal sent?
Is 0.7 - 1.8 V applied to JK101 pin 2?
Is approx. 1.7 V applied to IC103 pin 79?
Is the voltage 0 V on R192 (IC106 pin 89 side) ?
Replace C127 or C134. Is the problem solved?
Replace JK101. Is the problem solved?
IC103 and IC106 are defective.
CONFIDENTIAL
NO
YES
YES
YES
NO
NO
YES
YES
YES
NO
NO
TM200 1ADJUSTMENTS, PERFORMANCE CHECK, AND FIRMWARE UPGRADE
YES
The built-in microphone is defective or in a poor contact with
the PWB.
L101, L102, and C101 are defective.
NO
Is 1.2 - 2.1 V applied to TP119?
Is 2.4 - 2.5 V applied to TP176?
NO
Is 2.4 - 2.5 V applied to IC103 pin 76?
NO
IC103 is defective.
NO
Is approx. 1.7 V applied to IC103 pin 96?
NO
R263 and R130 are defective.
NO
R192 is defective. (Headset mode is set.)
YES
C126 or C133 is defective.
YES
Hands free kit is defective.
C104, R112, and V101 are defective.
NO
Is 0.7 - 1.8 V applied to TP120?
Is 2.4 - 2.5 V applied to TP176?
NO
Is 2.4 - 2.5 V applied to IC103 pin 76?
NO
IC103 is defective.
NO
Is approx. 1.7 V applied to IC103 pin 95?
NO
R262 and R129 are defective.
NO Jack JK101 is defective, or the jack plug is in a poor contact
with hands free kit (Handset mode is set.)
YES
C127 or C134 is defective.
JK101 is defective, or the jack plug pin 2 is in a poor contact
YES
with hands free kit.
2 – 30
YES
NO
YES
R125 is defective.
YES
R115 and C108 are defective.
YES
IC103 is defective.
YES
NO
YES
R122 is defective.
YES
R115 and C108 are defective.
YES
IC103 is defective.