Sharp LC-20A2E (serv.man2) Service Manual ▷ View online
LC-20A2E
13
TROUBLE SHOOTING TABLE
(Continued)
No picture
Check all the settings microprocessor's adjust process menu.
Is input at pin
74 of IC801
normal?
Check the AV2
line and their
peripheral parts.
Check the
SC2001,
SY-line, SC-line
and their
peripheral parts.
No
No VIDEO 2
output
Is input at pins
71 and 72 of
IC801 normal?
No
No S-VIDEO
output
Is input at pin
70 of IC801
normal?
Check the
V2VO line and
their
peripheral parts.
No
No line
output
Is input at pins
1, 2, 3, 56, 57
and 79 of IC801
normal?
Is output at pins
11, 13 and 16
of I4 normal?
Check IC801
and their
peripheral parts.
Check I13 and
their
peripheral parts.
Check I9 and
their
peripheral parts.
Check I4 and
their
peripheral parts.
Is output at pins
11, 13 and 16
of I13 normal?
Yes
Yes
No
No
No
No TELETEX
output
Is output at pins
44~49 of I9
normal?
Yes
No
LC-20A2E
14
TROUBLE SHOOTING TABLE
(Continued)
No picture
Check all the settings microprocessor's adjust process menu.
Is source GND
normal?
Is CSCOM
waveform
normal?
Check R1212,
FB1201 and their
peripheral parts.
Check IC1109,
Q1101, Q1102,
D1101, R1120,
R1130 and their
peripheral parts.
Check R1231
and their
peripheral parts.
Yes
No
No
Becomes
dark
No
Time passes,
becomes
dark
Is gate GND
normal?
Is gate clock
(GCK) normal?
Is output at pin
3 of IC1205
normal?
Yes
No
Check D1201
and their
peripheral parts.
No
Is B-5.5V being
outputted?
Is VCC being
outputted?
Check T701's
secondary +5V
outputs line?
Yes
No
Is GSP
waveform
normal?
Check R1223
and gate aray
peripheral parts.
Yes
Yes
No
Check R1223
and their
peripheral parts.
Becomes
white.
Is 3.3V VHS
being
outputted?
Is source clock
(CK) normal?
Check +3.3V
outputs line of
IC752.
Check R1210,
R1211 and their
peripheral parts.
Check FB1203
and gate aray
peripheral parts.
Is output of LBR
and HG
normal?
Yes
Yes
No
No
No
Vertical line
output
No picture
Check all the settings microprocessor's adjust process menu.
Is output of
R0~R5
normal?
Is output of
G0~G5
normal?
Is output of
B0~B5
normal?
Check R1202,
R1203 and their
peripheral parts.
Check R1204,
R1205 and their
peripheral parts.
Check R1206,
R1207 and their
peripheral parts.
Check T701's
secondary +5V
outputs line.
Yes
Yes
No
No
Colour is
unusual
Is VLS 5V
being
outputted?
No
Picture
image is
gloomy
Is in/output of
SPIO and
SPOI normal?
Check R1209
and their
peripheral parts.
No
No picture
image
inversion
Is output V0,
V16, V32, V48
and V63
normal?
Check IC1106,
IC1107, IC1108
and their
peripheral parts.
No
Gradation
defect
Is output of U/D
normal?
Check Q1201
and their
peripheral parts.
Yes
No
LC-20A2E
15
TROUBLE SHOOTING TABLE
(Continued)
No sound
Check all the settins microprocessor's adjust process menu.
Is the pin 53 of
IC2001 in the
"L" state?
Is output at pins
26 and 27 of
IC901 normal?
Is output at pins
1 and 7 of
IC903 normal?
Yes
Yes
No
No
No
No
No
No sound
from front
speakers
Is output at pins
3 and 5 of
IC303 normal?
Yes
Is output at pins
8 and 12 of
IC3305 normal?
Yes
Muting effect is
on. Check the
FSMUTE line.
Check IC901
and their
peripheral parts.
Check IC903
and their
peripheral parts.
Check IC303
and their
peripheral parts.
Check IC3305
and their
peripheral parts.
Check front
speaker and
connection
cable.
Yes
Is the pin 53 of
IC2001 in the
"L" state?
Is output at pins
24 and 25 of
IC901 normal?
Is output at pins
1 and 7 of
IC304 normal?
Yes
Yes
No
No
No
No
No
Is output at pins
42 and 43 of
SC402 normal?
Yes
Is output at pins
6 and 7 of
P4004 normal?
Yes
Muting effect is
on. Check the
FSMUTE line.
Check IC901
and their
peripheral parts.
Check IC304
and their
peripheral parts.
Check SC402,
SC901 and their
peripheral parts
and connection.
Check P4004
and their
peripheral parts
and connection
cable.
Yes
Check the
J4001 line.
No sound
from
headphone
Is output at pins
36 and 37 of
IC901 normal?
Is output at pins
1 and 7 of
IC902 normal?
Check IC901
and their
peripheral parts.
Check IC902
and their
peripheral parts.
Yes
Yes
No
No
No sound
from output
line
TV sound
failure
Is output at pins
15 and 16 of
SC402 normal?
Is output at pins
17 and 18 of
W9 normal?
Check SC402,
SC901 and their
peripheral parts
and connection.
Check W9 and
their peripheral
parts and
connection.
Yes
No
No
Check the
U1 line.
Yes
Is output at pin
1 of W7 tuner
normal?
Is input at pin
67 of IC901
normal?
Check the tuner
and their
peripheral parts.
Check IC901,
MONOS/SIF
line and their
peripheral parts.
Yes
No
No
LC-20A2E
16
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