LC-19A1E (serv.man4). Troubleshooting Table - Sharp TV Service Manual (repair manual). Page 6

LC-19A1E-BK/WH

4 – 6

                                    

No audio output during UHF/VHF 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)                                     

YES

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

NO

(MAIN-UNIT)                 

YES

Is the audio signal (INLP/INRP) output form pins (25) 
and (23) of IC302 (A-CODEC) properly? 

NO

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

YES

Is the audio signal L-CH output to pins (44-46) and (39-
41) of IC303 (POWER-AMP) and also the audio signal 
R-CH output to pins (20-22) and (15-17) of IC303 
(POWER-AMP) properly? 

NO

Check UR12V power supply input pins (3) and (48) of IC303 
(POWER-AMP) or peripheral circuits.

YES

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

NO

Check SP- Connector (P301) and peripheral circuits. 

YES

Check SP-BOX (right and left) and WIRE HARNESS. 

(MAIN-UNIT)
Is the MPX/PC/HDMI_A_L/R signal output to pins (11) and (15) 
of IC301 (A-Selector)? 

YES

Check either pins (9) and(10) of Connector SC1202 or pins (9) 
and(10) of Connector P501. Or check peripheral circuits.

                                    

NO

Is the audio signal (DVPM2_L/R) output from pins (B23) and 
(D23) of IC801 (DVP-M2)?

YES

Check pins of (6) and (1) of IC301 (A-Selector) and peripheral 
circuits.

                                    

NO

Is the audio signal (SIF) input to pin (A21) of IC801 (DVP-M2)?

YES

Check the power supply B1.5V pins (C18) and B3.3V pins (A18)/
(A22) are supplied to IC801 (DVP-M2).
Or check peripheral circuits.

(AV-UNIT)                                    

NO

Is the SIF signal output from pin (14) of TUNER (TU501)?

YES

Confirm pin (7) of Connector SC1202 or pin (7) of Connector 
P501. Or please check the peripheral circuit.

                                    

NO

Check whether the B5V power are supplied to pin (3) of TUNER 
(TU 501) respectively. Check SDA/SCA signal of pins (11) (10) 
and AGC signal of pin (7).

YES

Replace TUNER (TU501).