Read Sharp LL-171ME Service Manual online
LL-171ME
TROUBLESHOOTING
4 – 2
Fuse (F3) is not blown out?
(Yes)
(No)
Replace Fuse (F3).
Pictures appear when AV is input?
TV tuner (UT13) is defective.
(No)
(Yes)
Go to "No video appears".
(No)
Check "Picture line".
(No)
Check UT3 and circuits
around it.
around it.
(No)
Check IIC bus line and
around it.
around it.
Check regulator (U3) and circuits
around it.
around it.
Fuse (F2) is not blown out?
Replace LCD unit with a new one.
(Yes)
(No)
Replace Fuse (F2).
(No)
Check cable and related parts.
Check regulator U7 and circuits
around it.
around it.
PC is Sync On Green?
(No)
(Yes)
Sync On Green is input (R43)?
(Yes)
Sync On Green is output
(Pin 65 of U19)?
(Pin 65 of U19)?
(Yes)
RGB signals (R42, R43, R44) are
input?
input?
(No)
HSYNC is input (R67)?
(Yes)
(Yes)
(Yes)
(Yes)
(No)
HSYNC is output (at Pin 66 of
U19)?
U19)?
Check U19 and circuits
around it.
around it.
(No)
RGB signals (R42, R43, R44) are
input?
input?
Check RGB signals from
W2 to AD9883A (U19).
W2 to AD9883A (U19).
(Yes)
(Yes)
(No)
The signal between PW166
(U21) and THC63LVDM83A
(U24) is normal?
(U21) and THC63LVDM83A
(U24) is normal?
Check circuits around
PW166 (U21) and
THC63LVDM83A (U24).
PW166 (U21) and
THC63LVDM83A (U24).
(No)
The signal between
THC63LVDM83A (U24) and W5
is normal?
THC63LVDM83A (U24) and W5
is normal?
(Yes)
LCD unit cable and related parts
are normal?
are normal?
(No)
TV tuner Video Out output (Pin
12 of UT1) is normal?
12 of UT1) is normal?
(Yes)
5-V voltage is input to TV tuner
(Pins 3, 13 of UT1)?
(Pins 3, 13 of UT1)?
(Yes)
(Yes)
IIC bus (Pins 4, 5 of UT1) is
normal?
normal?
Check circuits around
THC63LVDM83A (U24)
and W5.
THC63LVDM83A (U24)
and W5.
(No)
Video signals (composite SCART
, S) are input to VPC3230 (UT8)?
, S) are input to VPC3230 (UT8)?
Check each video signal
line and AV connector and
cable.
line and AV connector and
cable.
(Yes)
(No)
3.3-V voltage is input to VPC3230
(Pins 10, 26, 29, 36, 45, 52 of UT8)?
(Pins 10, 26, 29, 36, 45, 52 of UT8)?
Check U10 and circuits
around it.
around it.
(Yes)
(No)
5-V voltage is input to VP3230
(Pins 59, 69, and 76 of UT8)?
(Pins 59, 69, and 76 of UT8)?
Check UT3 and circuits
around it.
around it.
(Yes)
(No)
IIC bus (Pins 13, 14 of UT8) is
normal?
normal?
Check IIC bus line and
around it.
around it.
(Yes)
(No)
The signal between VPC3230
(UT8) and PW1231 (U29) is
normal?
(UT8) and PW1231 (U29) is
normal?
Check VPC3230 (UT8)
and circuits around it.
and circuits around it.
(Yes)
(No)
The signal between PW1231
(U29) and PW166 (U21) is
normal?
(U29) and PW166 (U21) is
normal?
Check PW1231 (U29) and
circuits around it.
circuits around it.
(No)
The signal between AD9883A (U19)
and PW166 (U21) is normal?
and PW166 (U21) is normal?
Check circuits around
AD9883A (U19) and
PW166 (U21).
AD9883A (U19) and
PW166 (U21).
(No)
Check RGB cable and
connector W2.
connector W2.
Check RGB cable and
connector W2.
connector W2.
(No)
Check U19 and circuits
around it.
around it.
(No)
Check RGB signals from
W2 to AD9883A (U19).
W2 to AD9883A (U19).
(Yes)
(Yes)
The signal between AD9883A (U19)
and PW166 (U21) is normal?
and PW166 (U21) is normal?
(No)
Check circuits around
AD9883A (U19) and
PW166 (U21).
AD9883A (U19) and
PW166 (U21).
PC screen is not displayed.
Go to item
.
Go to item
.
Go to item
.
No TV picture is displayed.
No video appears
Go to item
.
Regulator (UT3) of 1 pin is input?
(Yes)
(Yes)
(Yes)
(No)
(No)
(No)
Replace UT3.
Replace U11.
Replace U12.
Regulator (U11) of 1 pin is input?
4pin of U12 have fallen
on ground ?
on ground ?
Check regulator Q2 and
LCDPWON signal.
LCDPWON signal.
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