Sharp LL-T19D1 Service Manual ▷ View online
LL-T19D1
TROUBLE SHOOTING
5 – 1
CHAPTER 5. TROUBLE SHOOTING
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
Yes
Yes
Yes
Yes
Yes
1) PC is turned off?
2) RGB/DVI cable is disconnected?
3) Synchronizing signal is output from RGB
2) RGB/DVI 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/DVI
cable with a new one.
cable with a new one.
LED turns on in orange?
Check power input system.
1) AC adapter
* Normal?
* Connected properly?
2) Blown out fuse?
3) Check +5V, 3.3V are output?
4) LED
* Check LED for breakage.
* Check the cable for disconnection.
Replace any defective unit.
[ 1) Power/inverter PWB, 2) Main PWB,
3) Switch PWB ] with a new one.
[ 1) Power/inverter PWB, 2) Main PWB,
3) Switch PWB ] with a new one.
Backlight turns ON?
Check for RGB/DVI cable
input signal.
input signal.
Replace RGB/DVI cable.
Check each pin terminal.
Normal
Normal
Normal
Defective
Defective
* Check power/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 power/inverter
PWB unit with a new one.
PWB unit with a new one.
A
LL-T19D1
TROUBLE SHOOTING
5 – 2
A
Screen does not operate normally.
Check RGB/DVI cable.
Defective
Replace RGB/DVI cable
with a new one.
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
(Press and hold MENU and
c
/MODE 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.
2) Is the power supply of IC turned ON?
3) Check if control signal is output of IC.
4) Check if LCD 12V 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-T19D1
CIRCUIT DIAGRAM
6 – 1
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
1/7
CHAPTER 6.
C
IRCU
IT DIAGRA
M
LL-T19D1
CIRCUIT DIAGRAM
6 – 2
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
2/7
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