LC-37XD1E (serv.man4). Troubleshooting Table - Sharp TV Service Manual (repair manual). Page 15

LC-37XD1E/RU

4 – 15

<When EXT3 is used for external input>                                                                        No picture on the display (5)

No EXT3 output of the external input system. 

No EXT3-Y/C output of the external input system.  

Checklist; 

  1)  Is"INPUT SOURCE" button

on the remote control set up correctly? ... See the operation manual and set "INPUT SOURCE" to "EXT3".

  2)  Is MENU-Picture-Backlight/Contrast/Brightness set to "MIN" ? ... Set it to an appropriate level.
  3)  Check the connection to the external device ... Connect it correctly as per the operation manual for the device.

Is composite video signal 
sent to pin (1) of A/V-IN-
TERMINAL
(J1201) ?   

NO

Check external connec-
tion, input setting, A/V-
IN-TERMINAL (J1201) 
and peripheral circuits.      

Is Y/C signal sent to pins 
(11) and (7) of  S-TERMI-
NAL  (J1201) ?    

NO

Check external connection, 
input setting, S-TERMINAL  
(J1201) and peripheral cir-
cuits  

YES

YES

Is composite video signal 
(IN3-  CVBS) sent to 
input terminal pin
(4) of  IC1201 (SW) ?  

NO

Check A/V-I N-TERMI-
NAL (J1201) and periph-
eral circuits.     

Is Y3 signal (IN3-Y) sent 
to Input  terminal pin (6) of 
IC1201 (SW) ?     

NO

Check S-TERMINAL 
(J1201) and peripheral cir-
cuits.    

YES

YES

Is composite video sig-
nal  (IN3(V)) sent to input 
terminal pin (AB20) of 
IC3002
(V-PRO) ?  

NO

Check CONNECTOR 
(SC2703/P1102 ), 
IC3002 (V-PRO.)  and 
peripheral circuits.      

Is Y/C signal (IN3Y/IN3C) 
sent to input terminal pins 
(AB20) and (AC20) of 
IC3002 (V-PRO.) ?    

NO

Check CONNECTOR 
(SC2703/P1102 ), IC3002 
(V-PRO.) and peripheral cir-
cuits.    

YES

YES

Is LVDS video signal (TA1

± -TD1±) sent to pins  (AB8)/(AC8) - (AB3)/(AC3) of IC3002 (V-PRO.), and 

is CLK signal (CK1

±) sent to pins (AB5)/(AC5)?

Is LVDS video signal (TA2

± - TD2±) sent to pins  (AC2)/(AC1) - (V2)/(V1) of IC3002 (V-PRO.), and is 

CLK signal (CK2

±) sent to pins (Y2)/(Y1)?  

NO

Check pins (G14)/(U10) of 
BU3.3V line of IC3002 (V-
PRO.), pins  (G10)/(N17) of 
BU2.5V line,pins  (U16)/
(G12) of BU1.8V line and 
peripheral circuits.

YES

Is LVDS video signal (TA1

± - TD1±) sent to pins (3)/(2) -(12)/(11) of CONNECTOR CN1 of LCD-

CONT-UNIT, and is CLK signal (CK1

±) sent to pins (10)/(9)?

Is LVDS video signal (TA2

± - TD2±) sent to pins (17)/(16) -(26)/(25) of CONNECTOR CN1 of LCD-

CONT-UNIT, and is CLK signal (CK2

±) sent to pins (24)/(23)?  

NO

Check CONNECTOR 
(SC2302, CN1) and HAR-
NESS WIRE (LV).

YES

  Is power (+12V) supplied to pins (1) - (5) of CONNECTOR CN2 in LCD-CONT-UNIT?  

NO

Check CONNECTOR 
(CN2,P707) and HAR-
NESS WIRE (PL).

YES

 Replace LCD-CONT-UNIT.