Sharp LC-20B8US, Руководство по обслуживанию

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29
LC-20B8U-S
LC-20B9U-S
LC-20B9U-SM
TROUBLE SHOOTING TABLE
No or
Wr
ong Picture
Are the w
a
v
e
fo
rms at
pins (84), (89) and (90) of IC801 as specified?
Chec
k IC801 and its
per
ipher
al circuits as
w
ell as the LCD panel
v
oltage and w
a
v
e
fo
rm
.
Chec
k the related lines
,
IC801 itself and its per
ipher
al circuits
.
Are the w
a
v
e
fo
rms at the signal
input pins of IC801 as specified? TV/Composite … Pin (40) S
Video … Pins (42) and (31)
Component … Pins (21), (33) and (44)
Chec
k the IC801 signal
input line
.
Chec
k IC801 and its
per
ipher
al circuits
.
No
No
No
Yes
Yes
Yes
Does the IC801 test patter
n appear
proper
ly?
No
No P
o
wer (P
o
wer LED indicator still in red)
Go to the adjustment process mode
.
Mo
v
e
the cursor to ERR
OR NO RESET
and clic
k on it (to reset to z
ero).
T
u
rn
off the po
w
e
r.
Is the po
w
er tur
ned on again?
1
MODEL
A628
INCH SIZE
20
ERR
OR NO RESET
0
PUBLIC MODE
OFF
V
-CHIP
1
EXT CONTR
OL
OFF
VER R
OM
*.
**
A GAIB
U
*.
***
Note:
This model is equipped with the lamp error detection function that detects the current flo
wing into the fluorescent lamp and protects the bac
klight lamp dr
iv
e circuit.
If a lamp error is detected, the microprocessor interr
upts the unit and the ERR
OR NO
RESET setting will go up
.
When the ERR
OR NO RESET setting has reached "5", the microprocessor tur
ns and
k
eeps off the unit's po
w
e
r.
T
o
resume the po
w
e
r,
tak
e the abo
v
e
procedure to clear the
ERR
OR NO RESET setting.
Check the following points. (1) Backlight lamp (2) Inverter circuit Sub PWB F6701, Q6719, Q6720, Q6721, Q6722, Q6723,
Q6724 and their peripheral parts as well as pins (187) of IC801, Q7752
(3) Lamp error detection circuit Q6703, Q6704, IC6701 and their peripheral parts
as well as pin (42) of IC2001