Sharp LL-T17A3 Service Manual ▷ View online
LL-T17A3
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.
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) AC adapter
* Normal?
* Connected properly?
2) Blown out fuse (F1, F02, F03)?
3) Check +5VX, 3.3VX, 3.3VA, VDD, VD
and VLCD are output?
4) LED
* Check LED for breakage.
* Check the path between W04 and
* Normal?
* Connected properly?
2) Blown out fuse (F1, F02, F03)?
3) Check +5VX, 3.3VX, 3.3VA, VDD, VD
and VLCD are output?
4) LED
* Check LED for breakage.
* Check the path between W04 and
IC15.
* Check the cable for disconnection.
Replace any defective unit.
[ 1) AC adapter, 2) Main PWB,
3) Switch PWB ] with a new one.
[ 1) AC adapter, 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 W05.
of W05.
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-T17A3
TROUBLESHOOTING
5 – 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 (IC02).
2) Is the power supply of IC21 and IC22 turned
ON?
3) Check if control signal is output (IC21, IC22).
4) Check if VLCD voltage is output normally.
(Check if F03 is blowout.)
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-T17A3
CIRCUIT DIAGRAM
6 – 1
A
B
C
D
876
5
4
3
21
D
C
B
A
A
B
C
D
876
5
4
3
21
D
C
B
A
A
B
C
D
876
5
4
3
21
D
C
B
A
A
B
C
D
876
5
4
3
21
876
5
4
3
21
D
C
B
A
CH
APTER
6. CIR
CUIT
DIAGRAM
LL-T17A3
PWB LAYOUT
7 – 1
CH
APTER
7. PWB
L
A
YOUT
A s
ide
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