Sharp TU-GA1U-S, Service Manual

Page: 26 / 186

26
TU-GA1U-S
TU-GAD
TROUBLE SHOOTING TABLE
(Continued)
No audio output (1)
No headphone audio output
Check between pins (26) and (27) (OUT
L/R) of IC2702 and HPAMP (IC2502), audio
mute (Q2501) and headphone terminal
(J2402), as well as their peripheral circuits.
NO
NO NO
NO
NO
NO
Is there normal audio output in IC2501
(Multi Sound Processor)?
Check pins (37) and (38) (SC10 OUT L/R)
of IC2501.
Check between pins (37) & (38) (SC10
OUT L/R) of IC2501 (Multi Sound
Processor) and pins (1) & (13) of monitor
switching IC1108.
Is there normal audio output for each?
Check between pins (1) & (13) of IC1108
and pins (2) & (5) of monitor audio output
terminal (J1105).
Check the headphone plug check circuit.
Check between headphone (pin (4) of
J2402) and pin (7) of IC1102.
No monitor audio output
Check if monitor audio output is set to
"variable" or if headphone is connected.
Is there normal audio output from the
main unit? Check pins (9) and (7) (L/R
OUT) of the connector (P1105).
Check between pins (9) & (7) (L/R OUT)
of P1105 and pins (1) & (13) of monitor
switching IC1108. Is there normal audio
output for each?
Check between pins (1) & (13) of IC1108
and pins (2) & (5) (Q1102, Q1103) of
monitor audio output terminal (J1105).
No BS monitor audio output
No audio output (2)
No audio output during BS reception
Are there normal audio outputs at pins
(33) and (34) (SC2 OUT L/R) of
IC2501 (Multi Sound Processor) to
pins (32) and (33) of IC2702?
No audio output during UHF/VHF
reception
Is the volume icon set on speaker
when volume key is operated? If monitor output is set to "variable" in the
main menu, change the setting to "fixed".
Are there normal inputs and outputs
of I2S/LRCK, BICK, SDTO and SDTI
signals between IC2702 and IC2700
(DSP)?
Are there normal audio outputs at pins
(28) and (29) (AOUT L/R) of IC2702?
Check between pins (33) & (34)
(SC2 OUT L/R) of IC2501 (Multi
Sound Processor) and pins (32) &
(33) of IC2702.
Check IC2702 and its peripheral
circuits.
NO
Are there normal signal inputs at pin
(2) of IC3805 and pin (2) of IC3812
(AV SW)? Check between pins (9) & (7) (L/R
OUT) of P1105 and pins (59) & (61)
of IC3800 (AV SW).
Are there normal signal inputs at pin
(3) of IC3805 and pin (3) of IC3812
(AV SW) to pins (56) and (57) of
IC2501 (Multi Sound Processor)?
Is there normal signal input at pin (67)
(SOUND IF1) of IC2501 (Multi Sound
Processor)?
NO
YES
YES
YES
YES
YES
YES
YES
NO
NO
NO
Are there normal audio outputs at pins
(28) and (29) of IC2702 to pins (13) and
(15) of P3801 (1-bit amplifier input)?
Check the circuits between pins (28) &
(29) of IC2702 and pins (13) & (15) of
P3801 (1-bit amplifier input.)
NO
Is relay switching done normally from
AUDIO I/F PWB P6003 to RY6001
(speaker switching) and RY6000
(speaker A/B switching)?
Check the 1-bit amplifier and its
peripheral circuits.
NO
Is the volume icon set on speaker
when volume key is operated?
Is there normal SIF output from
tuner? (Pin (14) of TU1101)
Check TU1101 (U/V tuner) and its
peripheral circuits.
NO
NO
NO