DOWNLOAD Sharp LL-171A Service Manual ↓ Size: 2.76 MB | Pages: 44 in PDF or view online for FREE

Model
LL-171A
Pages
44
Size
2.76 MB
Type
PDF
Document
Service Manual
Brand
Device
Monitor / Complete
File
ll-171a.pdf
Date
PREV: Sharp LL-151-3D (serv.man2) User Manual / Operation Manual

Sharp LL-171A Service Manual ▷ View online

LL-171A-W/B/LL-171G-W/B
TROUBLESHOOTING
5 – 1
CHAPTER 5. TROUBLESHOOTING
■
 NO POWER SUPPLY
* Inverter cable  is separated?
* Inverter cable is disconnection?
* Check the output of each pin
  2 pin (ON/OFF) 4pin (DIM)
No power supply
Does LED turns on in green 
when power switch is turned 
on?
No
No
No
No
No
Yes
Yes
Yes
Yes
Yes
No output +5V, 12V from
power supply unit.
Yes
Replace power supply unit.
1) PC is turned off?
2) RGB cable is disconnected?
3) Synchronizing signal is output from RGB 
cable?
Check whether the unit is in power save 
mode (synchronizing signal is not input.).
Synchronizing signal is input to main PWB?
Replace RGB cable 
with a new one.
LED turns on in orange?
Check power input system.
Replace any defective unit.
[ 1) Power supply PWB, 2) Main PWB,  
3) Switch PWB, 4) Audio PWB] with a new one.
Backlight turns ON?
Check for RGB cable input 
signal.
Replace RGB cable.
Normal
Normal
Normal
Defective
Defective
*  Check inverter PWB unit.
Note: Use caution when checking output 
side because it has a high voltage. 
Replace LCD module lamp with 
a new one.
Replace inverter PWB 
unit with a new one.
A
1) Power  Inverter supply PWB Normal?
    Connected with the MAIN PWB properly?
2) Blown out fuse (D201)?
    Check VCC5V+, VCC2.5V and VCC3.3V
    are output?
3) Check POWER switch and LED for 
     breakage.
4) Check the Audio PWB of 12V connected
     too hastily.
LL-171A-W/B/LL-171G-W/B
TROUBLESHOOTING
5 – 2
Set volume to max and has the output
waveform appeared in 4, 9, 16, 21 of 
U12 pin?
Is connection of from a main PWB cable
to key PWB and a speaker cable normal?
No
Speaker defective.
Yes
No
No
No
Yes
Yes
■
 NO SOUND
■
 Screen does not operate normally.
A
Screen does not operate normally.
Check RGB cable.
Defective
Replace RGB cable with 
a new one.
Check screen condition by changing display modes.
Operate the "ALL RESET" to check if screen condition changes.
(Press and hold MENU and SELECT buttons while turning on power switch.)
Screen stays in black.
Screen stays in white.
Screen jitters or on-screen 
characters flicker.
Abnormal color
Check the following signals
1) Check if module control signal is output (U10).
2) Check if VLCD voltage is output normally.
Yes
No
Yes
No
Yes
No
CLOCK and PHASE 
can be adjusted?
Does abnormal area move on 
screen when BLACK LEVEL or 
CONT is changed after H-POS 
or V-POS is set?
Switch PWB defective
Main PWB defective.
LCD panel defective.
No sound
Audio cable defective.
Yes
No
U12 defect and so
Audio PWB defective.
Yes
Normal
Defective
Is the 7, 8, 19 pin of U12 about 12V?
Power supply inverter
PWB defective.
Check
3, 22pin of U12 signal
Has the input waveform
appeared in 5, 23 pin of U12 ?
U601 of Main PWB defect and so
Main PWB defective.
Is the signal outputted normally
from the source of an Audio signal?
LL-171A-W/B/LL-171G-W/B
CIRCUIT DIAGRAM & PWB LAYOUT
6 – 1
81X90 FOR SHARP
B5
5.PANEL INTERFACE
VLCD
PB[0..9]
PA[0..9]
B3
6.MCU
onBACKLITE
onPANEL_5V/3.3V
SDA
INT
CSZ
DDC_DAT
SCL
HWRESET
DDC_CLK
Volume
VCC5V
VCC12V
VCPU
RXD
TX
D
DVI-DDCSET
AdjBACKLITE
B2
4.SCALER
RIN
GIN
SOG
BIN
GNDR
GNDG
GNDB
HSYNC
VSYNC
R+
R-
G-
G+
B+
B-
CLK+
CLK-
CSZ
SCL
SDA
HWRESET
INT
Volume
PA[0..9]
PB[0..9]
VCC2.5
VCC3.3
VAA1
VAA2
VAA3
VAA4
VSYNC1
GNDR1
GIN1
GNDB1
GNDG1
BIN1
SOG1
RIN1
HSYNC1
B4
2.POWER
onPanel_5V/3.3V
onBACKLITE
AdjBACKLITE
VCC3.3
VCC2.5
VAA
1
VAA
2
VAA
3
VAA
4
VCC5V
VCC12V
VLCD
VCPU
B1
3.INPUT
RIN
GIN
BIN
VSYNC
GNDR
GNDG
GNDB
HSYNC
SOG
DDC_CLK
DDC_DAT
R+
R-
G-
G+
B+
B-
CLK+
CLK-
TX
D
RXD
RIN1
GNDR1
GIN1
GNDG1
GNDB1
VSYNC1
SOG1
HSYNC1
BIN1
DVI-DDCSET
PB[0..9]
PA[0..9]
VCC2.5
VCC5V
VAA1
VCC12V
VCPU
VAA2
VCC5V
VLCD
VAA1
VCC12V
VCC3.3
VCC3.3
VAA3
VLCD
VAA4
VAA
3
VCC2.5
VAA4
VCPU
VAA
2
■
 CIRCUIT DIA
GRAM
1.
 T
O
P
A
B
C
D
876
5
4
3
21
1
2
3
4
5
6
7
8
D
C
B
A
A
B
C
D
876
5
4
3
21
1
2
3
4
5
6
7
8
D
C
B
A
A
B
C
D
876
5
4
3
21
1
2
3
4
5
6
7
8
D
C
B
A
A
B
C
D
876
5
4
3
21
1
2
3
4
5
6
7
8
D
C
B
A
1/6
CH
APTER 6. 
CIR
CUIT
 DIAGRAM 
& PWB 
LAYOUT
LL-171A-W/B/LL-171G-W/B
CIRCUIT DIAGRAM & PWB LAYOUT
6 – 2
Brightness
TO-252
TO-263
GND
ON_OFF
VCC12V
GND
GND
GND
DIM
VCC12V
GND
VCC5V
GND
VCC5V
VCPU
VAA2
VAA1
VCC3.3
VCC5V
VCC5V
VAA3
VAA4
VCC5V+
VCC2.5
VCC5V+
VCC12V
VLCD
VCC5V
VCC5V
VCC3.3
VCC5V
VCC5V+
VCPU
VCC5V
VCC5V
R207
4.7K
 1/16W
Q202
PMBS
3904
3
2
1
D202
SR34
C203
0.1uF
FB202
NC 
D201
FUSE 600mA
+
C204
220uF/25V
U202
AIC1084-33M
3
1
2
VIN
ADJ
VOUT
D205
3.3V
Q20
1
PMB
S3904
3
2
1
R208
10K
 1/16W
C201
0.1uF
Q20
3
AO340
1
R203
1K
 1/16W
C214
0.1uF
CN201
Wafer 2x6
1
3
5
7
9
11
2
4
6
8
10
12
R211
10K
 1/16W
Q204
PMB
S3904
3
2
1
R202
10K
 1/16W
+
C202
220uF/25V
R212
4.7K
 1/16W
FB201
600 OHM
+
C206
NC
+
C208
10uF
R204
1K
 1/16W
U201
RT9164-25CL
3
2
1
VI
VO
GND
C210
0.1uF
R213
10K
 1/16W
+
C215
47uF/25V
R201
0
 1/16W
C207
0.1uF
D206
3.3V
D204
7.5V
R206
10K
 1/16W
R205
4.7K
 1/16W
C216
0.1uF
+
C211
100uF/25V
R209
0 1/16W
D203
BAV9
9
3
1
2
C205
0.1uF
R210
NC
C212
0.1uF
AdjBACKLITE
4
onBACKLITE
6
VAA14
VAA24
VAA34
VAA44
VCC3.3
4
VCC12V
6
onPanel_5V/3.3V
6
VLCD
5
VCPU
6
VCC2.5
4
VCC5V
3,6
VCPU
6
A
B
C
D
876
5
4
3
21
1
2
3
4
5
6
7
8
D
C
B
A
A
B
C
D
876
5
4
3
21
1
2
3
4
5
6
7
8
D
C
B
A
A
B
C
D
876
5
4
3
21
1
2
3
4
5
6
7
8
D
C
B
A
A
B
C
D
876
5
4
3
21
1
2
3
4
5
6
7
8
D
C
B
A
2/6
2.
 PO
WER
Page of 44
Display

Click on the first or last page to see other LL-171A service manuals if exist.

RANDOM: