LC-19D1EBK (serv.man5). Troubleshooting Table - Sharp TV Service Manual (repair manual). Page 5

LC-19D1E/S-BK/WH

4 – 5

No audio output during 
DTV reception 

Checklist :
1)  Is the volume set to MIN or MUTE on the remote control ? 

• • • Set the desired volume.

2)  Is ANT-CABLE disconnected or connected improperly ? 

• • • Connect it correctly as per the operation manual.

(AV-UNIT)

   

(DIGITAL-UNIT)

Is the audio signal (L/R) 
input to pins (17) and (18) 
of  IC501 (AV-SW)?

NO

Is the DTV-A-_L/R signal 
output from pins (7) and 
(1) of IC4605 (OP-AMP)?

YES

Check either pins (8) and 
(9) of Connector  SC4602 
or pins (8) and (9) of  
Connector P503, or 
check peripheral circuits.

YES

NO

Is the audio signal 
(TERMINAL_L/R) output 
from pins (34) and (33) of  
IC501 (AV-SW)?

NO

Check the power sup-
ply B9V pins (38) and  
peripheral circuits.

Is the audio signal (LEFT/
RIGHT_P/M) output from 
pins (25)(24) and (29)(28) 
of  IC4001 (DIGITAL-
PROCESSOR) ?

YES

Are LEFT_P/M and the 
RIGHT_P/M signal input 
to pins (5)(6) (3)(2) of 
IC4605 (AMP)? or check 
peripheral circuits.

(MAIN-UNIT)

YES

NO

Is the audio signal 
(LOUT2/ROUT2) output 
form pins (25)  and (23) of  
IC302 (A-CODEC) prop-
erly? 

NO

Check pins (1) and (4) 
of  IC302 (A-CODEC), 
pins (11) and (12) of  
Connector SC1202, 
audio-mute line (Q301/
Q302) or peripheral  
circuits.

Is the serial digital signal 
(TSOUT7) input to pin 
(36) of  IC4001(DIGITAL-
PROCESSOR)?

YES

Check the power supply 
3.3V pins (3-129) 2.5V 
pins (151-212) and 1.2V 
pins (8-204)  of IC4001 
(DIGITAL PROCES-
SOR). Or check periph-
eral circuits.

YES

NO

Is the audio signal L-CH 
output to  pins    (44-45) 
and (40-41) of  IC303 
(POWER-AMP) and also 
the audio signal R-CH 
output to  pins  (20-21) 
and (16-17) of  IC303 
(POWER-AMP) properly? 

NO

Check  UR12V power 
supply input pins (47) 
and (14)  of  IC303 
(POWER-AMP) or 
peripheral circuits. 

Is serial digital signal 
(FED7) input to  pin(12) of 
IC4005(BUFFER)?

YES

Check IC4405(BUFFER) 
or peripheral circuit.

YES

(AV-UNIT)

NO

Is the audio signal of  pins 
(1),(2),(3) and (4) of P301 
(SP-Connector) output 
normally ?

NO

Check SP- Connetor 
(P301) and peripheral 
circuits

Is the serial digital signal 
(FED[7]) output from pin 
(43) of  IC202 (DVB-T)?

YES

Check the connection 
between pin (10) of  
SC4601 and pin (10) of  
P202, or check periph-
eral circuit

YES

NO

Check SP-BOX (right and 
left) and WIRE HAR-
NESS.

Is the IF(D1/D2) signal 
output from pin (17)/(16) 
of Tuner (TU201)?

YES

Check IC202(DVB-T) or 
peripheral circuit. 

NO

Check the B5V/B5V 
(CONT)/IF5V power sup-
ply  pins (11)/(1)/(3) , SDA/
SCL signal pins (9)/(8) of 
Tuner (TU201). 

YES

Replace Tuner (TU201).