Sharp LC-37HV4E (serv.man20) Service Manual ▷ View online
25
LC-37HV4E
No sound comes out. (Connect to the AVC System and check.)
Is power supplied to each
IC in the audio unit?
IC in the audio unit?
Is an audio signal appearing
at pin (8) (L-IN) and pin (10)
(R-IN) of P3802?
at pin (8) (L-IN) and pin (10)
(R-IN) of P3802?
YES
Is an audio signal appearing
at pins (10) and (14) of
IC3812 (Audio Output)?
at pins (10) and (14) of
IC3812 (Audio Output)?
YES
YES
YES
YES
NO
Check around the
power regulator circuit
(IC3809, IC3810).
power regulator circuit
(IC3809, IC3810).
NO
Is an audio signal
appearing at pins (13)
and (20) of SC2202 in
the main unit?
appearing at pins (13)
and (20) of SC2202 in
the main unit?
NO
Check for output from the
AVC system side.
AVC system side.
NO
Are Q3812 and Q 3813
(MUTE Circuits)
operating?
(MUTE Circuits)
operating?
Is an audio signal appearing
at pins (24), (27), (28) and
(31) of IC3812 (Audio
Output)?
at pins (24), (27), (28) and
(31) of IC3812 (Audio
Output)?
YES
Check if RY3801 (for
Internal/External switching) is
operating properly.
Internal/External switching) is
operating properly.
NO
NO
Check D3828-D3831
for short-circuiting and
check the circuits
around IC3812.
for short-circuiting and
check the circuits
around IC3812.
NO
Check IC3801, IC3803,
IC3804-IC3807, and
IC3811 for I/O signals.
IC3804-IC3807, and
IC3811 for I/O signals.
Check around Q2012 and Q2014 and check the
wire connected between the main unit and
audio unit.
wire connected between the main unit and
audio unit.
The whole screen is whitish (LCD power supply)
Disconnect the FFC from CN4101,
CN4102 and CN4601-CN4604.
(Otherwise it may cause the panel to get
broken.)
CN4102 and CN4601-CN4604.
(Otherwise it may cause the panel to get
broken.)
Check the power supplies.
Check the power supplies to CN4101
and CN4102 in particular.
Check the power supplies to CN4101
and CN4102 in particular.
YES
Is the voltage of R4114 around 6V?
YES
Check the I/O voltages of IC4103,
IC4105 and IC4106.
IC4105 and IC4106.
Check the performance of Q4101
and Q4112 and check the
resistances around IC4102.
and Q4112 and check the
resistances around IC4102.
TROUBLE SHOOTING TABLE (Continued)
26
LC-37HV4E
8
7
10
9
6
5
4
3
2
1
A
B
C
D
E
F
G
H
CHASSIS LAYOUT
27
LC-37HV4E
17
16
19
18
15
14
13
12
11
10
28
LC-37HV4E
8
7
10
9
6
5
4
3
2
1
A
B
C
D
E
F
G
H
BLOCK DIAGRAM
LCD P
LCD Back Light
Monitor
DVI Connector (24pin)
(TMDS)
SC2201 (ZA017WJ)
•
TMDS 3X4
•
DDC 6
•
Audio L, R
•
Main Correspondence UART
•
FLASH Write Control
•
Power Control
•
Detection (Cable Connection, AVC System Start-up, AC
•
Remote Control Signal for SR
System Connector (2
SC2202 (Z2015C
(TMDS)
AU
Power Contro
DVI Receiver
SII861
QFP208 (TMDS)
IC2206 (SII861)
OSD Contro
OS Driver Control
17 (Address, et
16 (Data)
SDRAM
IC490
Dimmer Control, Im
OFL1, 2
R RGB
8X3X2
8X3X2
L RGB
8X3X2
8X3X2
OSD RGB
RGB 8X3
RGB 8X3
TMDS 3X4
DDC
EEP128K
EEP32K
EEP1K
INITIAL
ROM
HDCP KEY
ROM
EDID
ROM
RGB 8X3
RGB 8X3
CONF
CTRL
CPLD
CPLD
IC4303
(A345WJ)
SDRAM (OS_EVEN)
IC4702 (A312WJ)
CONF
FLASH
IC4301
IC4301
Rewrite
Connector
Rewrite
Connector
16 (Data)
17 (Address, etc)
LCD Controller
BGA265pin
(LCDCONT)
IC4501 (A475WJ)
OS Driver (EVEN)
QFP208pin
(OS_EVEN)
IC4701 (A332WJ)
OS Driver (ODD)
QFP208pin
(OS_ODD)
IC4901 (A332WJ)
CLK
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