Sharp LL-T15G3 (serv.man14) Service Manual ▷ View online
LL-T15G3
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 connector locking tape.
5) 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-T15G3
TROUBLESHOOTING
4 – 1
CHAPTER 4. 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
LL-T15G3
TROUBLESHOOTING
4 – 2
A
Screen does not operate normally.
Check RGB cable.
Defective
Replace RGB cable with
a new one.
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.)
(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.
characters flicker.
Abnormal color
Check the following signals
1) Check if module control signal is output (U1).
2) Check if VLCD voltage is output normally.
Yes
No
Yes
No
Yes
No
CLOCK and PHASE
can be adjusted?
can be adjusted?
Does abnormal area move on
screen when BLACK LEVEL or
CONT is changed after H-POS
or V-POS is set?
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.
LL-T15G3
CONNECTOR SIGNAL TABLE • CIRCUIT DIAGRAM • PWB LAYOUT
5 – 1
CHAPTER 5. CONNECTOR SIGNAL TABLE • CIRCUIT DIAGRAM • PWB LAYOUT
1. CONNECTOR SIGNAL TABLE
CONNECTOR P1
CONNECTOR P2
CONNECTOR P3
CONNECTOR P5
CONNECTOR P8
1
GND
2
BO7
3
BO6
4
BO5
5
BO4
6
GND
7
BO3
8
BO2
9
BO1
10
BO0
11
GND
12
GO7
13
GO6
14
GO5
15
GO4
16
GND
17
GO3
18
GO2
19
GO1
20
GO0
21
GND
22
RO7
23
RO6
24
RO5
25
RO4
26
GND
27
RO3
28
RO2
29
RO1
30
RO0
31
GND
32
GND
33
N.C
34
N.C
35
N.C
36
GND
1
GND
2
DCLK
3
GND
4
DE-O
5
VSYNC
6
HSYNC
7
N.C
8
GND
9
BE7
10
BE6
11
BE5
12
BE4
13
GND
14
BE3
15
BE2
16
BE1
17
BE0
18
GND
19
GE7
20
GE6
21
GE5
22
GE4
23
GND
24
GE3
25
GE2
26
GE1
27
GE0
28
GND
29
RE7
30
RE6
31
RE5
32
RE4
33
GND
34
RE3
35
RE2
36
RE1
37
RE0
38
VLCD
39
VLCD
40
GND
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)
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