Sharp LL-T15A4 Service Manual ▷ View online
LL-T15A4
DISASSEMBLY AND ASSEMBLY
3 – 1
CHAPTER 3. DISASSEMBLY AND ASSEMBLY
1. SEPARATING DISPLAY UNIT AND
STAND UNIT
1) Remove the screws and separate the display unit
1
from the stand
unit
2
.
2. REMOVING KEY BOARD
1) Remove the screws and then remove the rear cabinet.
2) Remove the screws and connectors, and then remove the KEY board.
3. REMOVING POWER SUPPLY/INVERTER
BOARD AND MAIN BOARD
1) Remove the hex. screws
A
and screws
B
, and then remove the shield.
2) Remove the screws
A
and then remove the ground lead.
3) Remove the connectors and screws
B
, and then remove the power
supply/inverter board.
4) Remove the connectors and screws, and then remove the main board.
4. REMOVING LCD MODULE
1) Remove the screws
A
and then remove the front cabinet
1
.
2) Remove the screws
B
, and then remove the frame
2
from the LCD
module
3
.
1
2
B
B
B
B
B
B
A
A
B
B
B
B
B
B
1
2
3
B
B
A
A
LL-T15A4
BLOCK DIAGRAM
4 – 1
CHAPTER 4. BLOCK DIAGRAM
■
■
■
■
MAIN PWB
R
G
B
G
B
H-sync
V-sync
Clock
SOG
DE
SDA SCL
H
V
V
SCL SDA
VLCD
+3.3Vx
+5Vx
ON/OFF
Speaker or Head phone
+5Vx
VLCD
MASCOTV
W78E516B
(MPU)
ADC
Sync
process
process
I2C
Bus
OSD
Panel
interface
Clock
generator
generator
D- SUB
U5
CS -5828
(LVDS)
24LC21
1084 -
3.3
PWM
24LC08
TFT
Panel
Power
MOS
AN7512
(Audio Amp.)
18 bit EVEN data
1084 -
3.3
Audio In
LL-T15A4
BLOCK DIAGRAM
4 – 2
■
■
■
■
CONNECTOR SIGNAL TABLE
CONNECTOR P1
CONNECTOR P3
CONNECTOR P5
CONNECTOR P8
CONNECTOR P10
1
SEL
2
GND
3
RX3+
4
RX3-
5
GND
6
CLK+
7
CLK-
8
GND
9
RX2+
10
RX2-
11
GND
12
RX1+
13
RX1-
14
GND
15
RX0+
16
RX0-
17
GND
18
GND
19
VCC
20
VCC
1
12V
2
GND
3
GND
4
5V
5
BRI_Min
6
INV_ON
1
POW1
2
GND
3
LED1
4
LED2
5
KEY1
6
KEY2
7
KEY3
8
KEY4
1
Red
2
Green
3
Blue
4
Ground
5
Ground
6
R-GND
7
G-GND
8
B-GND
9
+5V
10
Ground
11
N.C
12
(SDA)
13
H-sync
14
V-sync
15
(SCL)
1
CH2-
2
CH2+
3
CH1+
4
CH1-
LL-T15A4
TROUBLESHOOTING
5 – 1
CHAPTER 5. TROUBLESHOOTING
No power supply
Does LED turns on in green
when power switch is turned
on?
when power switch is turned
on?
No
No
No
No
No
No
LED turns on in red?
Yes
Yes
Yes
Yes
Yes
Yes
Yes
* Check LED for breakage.
* Check key cable for disconnection.
* Check key cable for disconnection.
No output +5V, 12V from
power supply unit.
Yes
Replace power supply unit.
Replace any unit (main PWB, SW PWB, cable)
which shows any defect, with a new one.
which shows any defect, with a new one.
1) PC is turned off?
2) RGB cable is disconnected?
3) Synchronizing signal is output from RGB
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.).
mode (synchronizing signal is not input.).
Synchronizing signal is input to main PWB?
Replace RGB cable
with a new one.
with a new one.
LED turns on in orange?
Check power input system.
1) Power supply PWB
* Normal?
* Connected properly?
2) Blown out fuse (F1)?
3) Check +5VX, 3.3VX, 3.3VA, VDD, VD
and VLCD are output?
4) LED
* Check LED for breakage.
* Check the path between P5 and U6.
* Check the cable for disconnection.
* Normal?
* Connected properly?
2) Blown out fuse (F1)?
3) Check +5VX, 3.3VX, 3.3VA, VDD, VD
and VLCD are output?
4) LED
* Check LED for breakage.
* Check the path between P5 and U6.
* Check the cable for disconnection.
Replace any defective unit.
[ 1) Power supply PWB, 2) Main PWB,
3) Switch PWB ] with a new one.
[ 1) Power supply PWB, 2) Main PWB,
3) Switch PWB ] with a new one.
Backlight turns ON?
Check for RGB cable input
signal.
signal.
Replace RGB cable.
Check each pin terminal
of P3.
of P3.
Normal
Normal
Normal
Defective
Defective
* Check inverter PWB unit.
Note: Use caution when checking output
Note: Use caution when checking output
side because it has a high voltage.
Replace LCD module lamp with
a new one.
a new one.
Replace inverter PWB
unit with a new one.
unit with a new one.
A
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