LC-19D1EBK (serv.man5). Troubleshooting Table - Sharp TV Service Manual (repair manual). Page 11

LC-19D1E/S-BK/WH

4 – 11

<0n input of the DTVtuner>                                                               No picture on the display (1)-1 

No picture appears on LCD during the DTV tuner reception.

YES

Checklist:
1) Is "INPUT SOURCE" button 

 on the remote control set up correctly ? 

• • • set it as "DTV" with the INPUT SOURCE button 

on the 

remote control.

2) Is MENU-Picture-Backlight/Contrast/Brightness set to "MIN" ? 

• • • Set it to an appropriate level.

3) Is the level of pin (9)(8) of tuner (TU201) at "H"? 

• • • These are serial communications lines (I2C) for the control. If it is "L", check whether 

something pulls it to "L".  (IC801 (A5)(C4)pin)

(AV-UNIT)

YES

Is the DTV-R/G/B signal  output from pin (4)/(3)/(2) of Connector 
P503? 
Is the DTV-CVBS signal output from pin (6) of connector P503? 

YES

Is the DTV-R/G/B signal input to pin (9)/(1)/(14) of IC507(SW)?
Is the DTV-CVBS signal input to pin (4) of IC508(SW)?

NO

Check the course between Connector P503 and IC507(SW).
Check the course between Connector P503 and IC508(SW).

YES

Is the SC-R/G/B signal output from pin (6)/(3)/(5) of IC507(SW)?
Is the DTV-CVBS signal output from pin (2) of IC508(SW)?

NO

Check pins (13) of B9V line of IC507, and soldering.
Check pins (3) of B9V line of IC508, and soldering.

(MAIN-UNIT)

YES

Is the SC-R/G/B signal input to pin (N1)/(J1)/(K2) of IC801(DVP-
M2)?
Is the DTV-CVBS signal input to pin (W1) of IC801(DVP-M2)?

NO

Check pins (16)/(17)/(18) of Connector SC1203, (16)/(17)/(18) 
of Connector P502 and  peripheral circuits. (At the RGB signal).
Check pins (14) of Connector SC1203, (14) of Connector P502 
and  peripheral circuits. (At the CVBS signal)

YES

Is LVDS video signal (RA 

± ~ RD ±) output from pins (P22)(P23) - 

(V22)(V23) of  IC801 (DVP-M2), and is RCLK signal (RCLK 

±) out-

put from  pins (U22) (U23)?

NO

Check pins (R19)/(D5) of B3.3V line of IC801 (DVP-M2), pins 
(D12) of  B1.5V line, pins (B6)(A6) of SDA1/SCL1 line and 
peripheral circuits.

YES

Is RSDS-R/G/B signal (R[0:2] 

±,  G[0:2]±, B[0:2]±) output from 

pins (53) -(72) of  IC9201 (RSDS-TRANSMITTER) , and is CLK 
signal (CK

±) output from pins (60) and (59)?

NO

Check pins (1) and (9) of  B3.3V line of  IC9201 (RSDS-TRANS-
MITTER), short circuits and  peripheral circuits. 

YES

Is RSDS-R/G/B signal (R[0:2] 

±, G[0:2]±, B[0:2]±) and CLK signal 

(CK

±) input to connector (SC9201) of  LCD-PANEL? 

(RSDS-R signal:22-27pin, RSDS-G signal:57-62pin, RSDS-B sig-
nal:66-71pin, CK 

±signal:33/32pin)

NO

Check  whether there is short-circuit at connector SC9201 of 
LCD-PANEL and also check peripheral circuits.

YES

Is liquid crystal drive power supply input to Connector SC9201 of 
LCD-PANEL?
(VLS-B14.6V=40/41/42pin, VGH_B32V=5/6pin,VGL_-6V=2/3pin, 
COM-BIAS=75/76/77pin)

NO

Please check REGULATOR-circuit of a defective voltage 
respectively. 

YES

 Replace LCD-PANEL.