Sharp 902SH, Service Manual

Page: 38 / 121

902SH
2 – 30
CONFIDENTIAL
8.2. Ring tones are heard from the speaker but voice is not.
8.3. Voice is heard from the speaker but ring tones are not.
9. The display does not appear on Main Display.
Is signal sent to R1612? IC1600 is defective.
IC1200 is defective.
Is the volume set to zero? Is sound heard after turning up the volume? OK.
Is clock sent to R1673? R1673 is defective.
Or IC1600 is defective.
IC1200 is defective.
Is the flexible PWB of the display securely
locked to CN3000? Unlock it, and then reinsert and lock it.
Replace Main Display.
Does the display appear? Are the following display parts in good condi-
tion?
C3050, C3053, C3055, C3056, C3057, C3058,
C3059, C3060, C3062, C3063, C3064, C3066,
C3067, C3068, C3069, C3070, D3000, D3003,
IC3006, R3019, R3021, R3062, R3063, R3018,
C3044 The display parts are
not mounted properly.
Main Display unit is defective. The battery is defec-
tive or not set; the
PWB is defective; the
battery needs to be
charged; the thin
coaxial cable socket is
mounted improperly or
broken; the main PWB
is defective; R3019
and R3063 are
mounted improperly;
or the display PWB is
defective.
Is 2.9
±
0.1 V applied to TP3026 and R3019?
Is 1.85
±
0.1 V applied to TP3027 and R3063?
Is the waveform from R3018 a 6.5 MHz pulse
wave?
Is the waveform from RA3010, RA3011,
RA3012, RA3013, R3017, and R3024 a pulse
wave? RA3010, RA3011,
RA3012, RA3013,
R3017 and R3024 are
defective or mounted
improperly.
CN3000 socket parts are defective, or the dis-
play PWB pattern is broken.
The thin coaxial cable
is broken, or the thin
coaxial cable socket is
in poor contact.
Is 3.2 V or more applied to TP3004?
Is the waveform of TP3002 a rectangular
wave? R3008A is mounted
improperly, or the dis-
play PWB and the
main PWB are defec-
tive.
IC3000 is defective.
YES
NO
YES YES
NO NO
YES
NO
NO
YES
NO NO
YES
YES
NO
YES
NO
YES
NO
YES
NO
YES
NO
YES