Sharp LC-46X8E/S/RU, Service Manual

Page: 49 / 166

LC-46X8E/S/RU
4 – 9
No picture on the display (1)
The picture doesn't appear in all modes.
MAIN UNIT:
Is LVDS signal output from 1st_channel and 2nd_channel of IC3301(VIDEO PROCESSER) in each mode?
TA1
±
(A14/B14), TB1
±
(A15/B15), TC1
±
(A16/B16), TD1
±
(A18/B18), TE1
±
(A19/B19), TCLK1
±
(A17/B17), TA2
±
(A20/B20), TB2
±
(C20/D19),
TC2
±
(D20/E19), TD2
±
(F20/G19), TE2
±
(G20/H19), TCLK2
±
(E20/F19)
YES
NO
Check IC3301 and its peripheral control circuits.
(IC2002 (UCON), IC8101 (DECODER), IC3501 (SRAM), IC3502
(SRAM), etc.)
Is the above-mentioned LVDS signal output to connector
(P2601)? NO Check the line between IC3301 and P2601.
YES
Is LCD controller's control signal normal? NO Check control signal line.
(R/L, U/D, TEMP1/2/3, DET_PNL12V, ROMSEL0/1)
LCD_CONT_UNIT: YES
Similarly, is the LVDS signal input to the connector (CN4804) of
LCD_CONT_UNIT? NO Check wire harness (LW).
YES
Check the LCD_CONT_UNIT.
No picture on the display (2)
The picture doesn’t come out when VHF/UHF is received.
TERMINAL UNIT:
Is IF signal output from pin (17) of TUNER (TU7501)?
NO Check whether I2C signal is normally accessed between TU7501
and IC7507 (COFDM).
YES
Is IF signal input to pin (1) and (2) of IC7504 (IF-DEMO)? NO Check the FL7502 (VIF_SAW) and their peripheral circuits.
YES
Is video signal (TUNER_CVBS) input from pin (17) of IC7504 to
pin (9) of IC506 (VIDEO_SELECTOR)? NO Check the line between IC7504 and IC506.
(Q7505, IC7508, etc.)
YES
Is CVBS signal (MAIN_Y/V) output from pin (52) of IC506 to pin
(2) of connector SC501? NO Check the line between IC506 and SC501.
MAIN UNIT: YES
Is CVBS signal (MAIN_Y/V) input to pin (2) of connector
SC1101? NO Check the connector SC501/SC1101.
YES
Is CVBS signal (MAIN_Y/V) input to pin (Y4) of IC3301
(VIDEO_PROCESSOR)? NO Check the line between SC1101 and IC3301.
YES
Refer to “The picture doesn't appear in all modes.”