DOWNLOAD Sharp LC-42SA1E (serv.man3) Service Manual ↓ Size: 1.01 MB | Pages: 23 in PDF or view online for FREE

     LC-42SA1E/RU

4 – 21

                                            
No EXT5 (HDMI) 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 “EXT5”.

2) Have you checked the type video signal sent from HDMI-connected external device? 

••• Confirm the type (it should “RGB”, “YCbCr 4:4:4” or 

“YCbCr 4:2:2”).

3) Have you checked the type of Color Matrix sent from HDMI-connected external device? 

••• Confirm the type (it should be “ITU601” or 

“ITU709”.)

4) Is ANT-CABLE disconnected or connected improperly? 

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

YES

Is “EXT5” selected with “INPUT SOURCE” button 

on the 

remote control?

NO

Select “EXT5” with “INPUT SOURCE” button 

on the remote 

control. 

YES

Is the type of video signal (Signal Type) from HDMI-connected 
external device set? 

NO

From MENU-Option-HDMI Setup-Signal Type, select a signal 
type (“RGB”, “YCbCr 4:4:4” or “YCbCr 4:2:2”).

YES

Is the type of color signal (Colour Matrix) from HDMI-connected 
external device set?

NO

From Option-HDMI Setup-Color Matrix, select a colour signal 
type (“ITU601” or “ITU709”)

YES

Is TMDS data (RX**

±signal) sent to pins (1) - (12) of EXT5 

(HDMI) terminal (SC1901)?

NO

Is I2C signal (SDA/SCL signal) sent to pins (16) and (15) of 
EXT5 (HDMI) terminal?
Check external connection and peripheral circuits.

YES

Is 8bit-DIGITAL signal (HDMI- R/G/B) sent from pins (110) - (144) 
of IC1905 (HDMI-RECEIVER)?

NO

Check power supply (3.3/1.8V) pins (99) and (74) of IC1905, 
SDA/SCL signal pins (29) and (30), and peripheral circuits.

YES

Is 8bit-DIGITAL signal (HDMI- R/G/B) sent to pins (73) - (50) of 
IC3002 (VCT)?

NO

Check SDA3/SCL3 signal pins (27) and (28), interface between 
IC1905 and lC3002, and peripheral circuits.

YES

Is LVDS signal (LVDS_0N/0P-3N/3P) sent from pins (141) and 
(140) - (129) and (128) of IC3002 (VCT), and is CLK signal 
(LVDS_CN/CP) sent from pins (132) and (131)? 

NO

Check pins (192), (170) and (133) of BU3.3V power line and
pins (185), (169) and (142) of BU1.8V power line of IC3002 
(VCT), and peripheral circuits.

YES

Is LVDS signal (LVDS_0N/0P-3N/3P) sent to pins (13) and (12) - 
(25) and (24) of CONNECTOR CN1 in LCD-CONT-UNIT, and is 
CLK signal (LVDS_CN/CP) sent to pins (22) and (21)? 

NO

Check CONNECTOR (P2305,CN1) and HARNESS WIRE (LV).

YES

Is power (LCD5V) supplied to pins (1) - (4) of CONNECTOR CN1 
in LCD-CONT-UNIT?

NO

Is LCD5V supplied to pins (31) - (28) of CONNECTOR (P2305)?
Check HARNESS WIRE (LV).

YES

Replace LCD-CONT-UNIT.

LC-42SA1E/RU

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Do all the fluorescent tubes light up?

NO

Check the individual fluorescent 
tubes for light-up failure.

YES

Replace any defective fluorescent
tubes with new ones.

YES

Is the power supplied to the inverter 
unit? (24V) (CN101 1-5pin)

NO

Check the connection between
power unit and inverter unit.

YES

Is the fuse in the inverter unit circuit 
functioning? (F1, F2, F6)

NO

Replace the blown-out fuse on the 
inverter unit.
Turn on the power again. 
If the fuse gets blown out again, 
check the short-circuited.

YES

Check drive trans and their peripheral
circuits as well as drive FET and their
peripheral circuits.

YES

Is the VCC power supplied to the
inverter control IC on the inverter 
unit?

NO

Check the circuit connected with the
VCC terminal on the inverter control
IC.

YES

Are there control signals (INV-ON, 
INV-BRT, PWM-SEL) at LA (CN101) 
on the inverter unit?

NO

Are there the INV-ON and INV-BRT
signals at LA and LB on the power 
unit, and the (INV-ON and INV-BRT)
signals at SC1702 on the main PWB?

NO

Check pins (5) and (7) of IC1710
(main PWB).

YES

Is the specified control signal inputted 
at INV-CTL-IC (U201) on the inverter 
unit?

NO

Check the line between LA (CN101) 
and INV-CTL-IC (U201).

YES

Are the DRIVE-FET at the primary 
side of DRIVE-TRANS functioning? 
(U101/U102)

NO

Replace INV-CTL-IC (U201) or check 
its peripheral circuits.

YES

Is the secondary circuit of DRIVE-
TRANS functioning?
(T1/T2

⋅⋅⋅⋅⋅⋅⋅⋅⋅T10)

NO

Replace the DRIVE-TRANS for
the fluorescent tubes, or check their
peripheral circuits.

     LC-42SA1E/RU

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LCD failure

Does a single or several vertical 
stripes appear on the LCD screen?

Replace the LCD panel.

Does a single or several horizontal
stripes appear on the LCD screen?

Do luminescent or black dots appear 
on the screen?

Is the on-screen image rippling or
distorted?

LCD failure

The backlight functions.
Does not the image come out in the 
LCD screen (screen black)?

Replace the LCD control unit.

Does the entire LCD screen look 
whitish all over?

Does the QS drive function?

Are there data bit drop-outs?
(No solution even when turning on 
and off the QS drive)

     LC-42SA1E/RU

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LCD failure

Does a single or several vertical 
stripes appear on the LCD screen?

Replace the LCD panel.

Does a single or several horizontal
stripes appear on the LCD screen?

Do luminescent or black dots appear 
on the screen?

Is the on-screen image rippling or
distorted?

LCD failure

The backlight functions.
Does not the image come out in the 
LCD screen (screen black)?

Replace the LCD control unit.

Does the entire LCD screen look 
whitish all over?

Does the QS drive function?

Are there data bit drop-outs?
(No solution even when turning on 
and off the QS drive)