40
LC-20B4U-S
LC-20B4U-B
TROUBLE SHOOTING TABLE
(Continued)
No picture and sound
No color
No TV
color
No S-VIDEO color
Yes
No
Do F3701and F3702
function?
Chec
k all the settings on the microprocessor
’s adjust process men
u.
No
Are secondar
y outputs
(+38V
, +9V
, +5V
, -11V) of
T3701 as specified?
Yes
Are the oscillation w
a
v
e
fo
rm
at T3701
’s pr
imar
y side as
specified?
Yes
No
Disconnect F3701 and
F3702.
Is the load side
shor
t-circuited?
Yes
No
Is an
y of
T3701
’s pr
imar
y
side
, Q3703 and S4701 shor
t-
circuited?
Chec
k J3701, its per
ipher
al
par
ts and connection cab
le
.
Replace F3701 and F3702.
Chec
k S4701 and
connection cab
le
.
Chec
k the secondar
y-side
load of
T3701.
Fluorescent lamp
failure
Yes
No
Does F6700, F6701,
F6702, F6703, and
F6704 function?
Yes
No
Is Pin (120) of IC1201 at
“H
”?
Yes
No
Are the oscillation w
a
v
e
fo
rms
at the pr
imar
y side of
T6700,
T6702, T6704, T6706,
and
T6708 as specified?
Yes
Replace F6700, F6701,
F6702, F6703, and F6704.
No
No
Is input at Pin (72) of IC806
as specified?
Chec
k SC3405, SC line and
per
ipher
al par
ts
.
Is input at Pin (71) of IC806 as specified?
Chec
k SC OUT1LINE and IC8201, Q8206, FL8206, IC8203, Q8202
Yes
Chec
k the line
, IC1201 and
its per
ipher
al par
ts
.
Yes
Yes
No
Is Pin (3) of P6706 at
“L
”?
Chec
k Q3601
Chec
k Q6700 - 6714,
T6700
- 6709 and their per
ipher
al
par
ts
.
Replace the fluorescent lamp
and chec
k the oscillation
w
a
v
e
fo
rm
again.
No VIDEO
color
Chec
k all the settings on the microprocessor
’s adjust process men
u
.
Interlace
No COMPONENT color
No
Is input at Pins (1) and (3) of
IC806 as specified?
Chec
k J3404,
VPCPB line
,
VPCPR line and per
ipher
al
par
ts
.
Pr
ogressive
No COMPONENT color
No
Is input at Pins (131) and
(133) of IC1201 as specified?
Chec
k J3404, CPB line
, CPR
line and per
ipher
al par
ts
.
Summary of Contents for LC-20B4U-B
Page 43: ...43 17 16 19 18 15 14 13 12 11 10 LC 20B4U S LC 20B4U B INVERTER A Unit INVERTER B Unit ...
Page 46: ...46 8 7 10 9 6 5 4 3 2 1 A B C D E F G H LC 20B4U S LC 20B4U B OVERALL WIRING DIAGRAM ...
Page 47: ...47 17 16 19 18 15 14 13 12 11 10 LC 20B4U S LC 20B4U B ...
Page 50: ...50 8 7 10 9 6 5 4 3 2 1 A B C D E F G H LC 20B4U S LC 20B4U B Ë MAIN Unit 1 6 ...
Page 51: ...51 17 16 19 18 15 14 13 12 11 10 LC 20B4U S LC 20B4U B ...
Page 52: ...52 8 7 10 9 6 5 4 3 2 1 A B C D E F G H LC 20B4U S LC 20B4U B Ë MAIN Unit 2 6 ...
Page 53: ...53 17 16 19 18 15 14 13 12 11 10 LC 20B4U S LC 20B4U B ...
Page 54: ...54 8 7 10 9 6 5 4 3 2 1 A B C D E F G H LC 20B4U S LC 20B4U B Ë MAIN Unit 3 6 ...
Page 55: ...55 17 16 19 18 15 14 13 12 11 10 LC 20B4U S LC 20B4U B ...
Page 56: ...56 8 7 10 9 6 5 4 3 2 1 A B C D E F G H LC 20B4U S LC 20B4U B Ë MAIN Unit 4 6 ...
Page 57: ...57 17 16 19 18 15 14 13 12 11 10 LC 20B4U S LC 20B4U B ...
Page 58: ...58 8 7 10 9 6 5 4 3 2 1 A B C D E F G H LC 20B4U S LC 20B4U B Ë MAIN Unit 5 6 ...
Page 59: ...59 17 16 19 18 15 14 13 12 11 10 LC 20B4U S LC 20B4U B ...
Page 60: ...60 8 7 10 9 6 5 4 3 2 1 A B C D E F G H LC 20B4U S LC 20B4U B Ë MAIN Unit 6 6 ...
Page 61: ...61 17 16 19 18 15 14 13 12 11 10 LC 20B4U S LC 20B4U B ...
Page 62: ...62 8 7 10 9 6 5 4 3 2 1 A B C D E F G H LC 20B4U S LC 20B4U B Ë TUNER Unit 1 5 ...
Page 63: ...63 17 16 19 18 15 14 13 12 11 10 LC 20B4U S LC 20B4U B ...
Page 64: ...64 8 7 10 9 6 5 4 3 2 1 A B C D E F G H LC 20B4U S LC 20B4U B Ë TUNER Unit 2 5 ...
Page 65: ...65 17 16 19 18 15 14 13 12 11 10 LC 20B4U S LC 20B4U B ...
Page 66: ...66 8 7 10 9 6 5 4 3 2 1 A B C D E F G H LC 20B4U S LC 20B4U B Ë TUNER Unit 3 5 ...
Page 67: ...67 17 16 19 18 15 14 13 12 11 10 LC 20B4U S LC 20B4U B ...
Page 68: ...68 8 7 10 9 6 5 4 3 2 1 A B C D E F G H LC 20B4U S LC 20B4U B Ë TUNER Unit 4 5 ...
Page 69: ...69 17 16 19 18 15 14 13 12 11 10 LC 20B4U S LC 20B4U B ...
Page 70: ...70 8 7 10 9 6 5 4 3 2 1 A B C D E F G H LC 20B4U S LC 20B4U B Ë TUNER Unit 5 5 ...
Page 71: ...71 17 16 19 18 15 14 13 12 11 10 LC 20B4U S LC 20B4U B ...
Page 72: ...72 6 5 4 3 2 1 A B C D E F G H LC 20B4U S LC 20B4U B Ë INVERTER A Unit ...
Page 73: ...73 6 5 4 3 2 1 A B C D E F G H LC 20B4U S LC 20B4U B Ë INVERTER B Unit ...
Page 76: ...76 6 5 4 3 2 1 A B C D E F G H LC 20B4U S LC 20B4U B MAIN Unit Side B ...
Page 79: ...79 6 5 4 3 2 1 A B C D E F G H LC 20B4U S LC 20B4U B TUNER Unit Side A ...
Page 82: ...82 6 5 4 3 2 1 A B C D E F G H LC 20B4U S LC 20B4U B INVERTER A Unit Side A ...
Page 84: ...84 6 5 4 3 2 1 A B C D E F G H LC 20B4U S LC 20B4U B INVERTER B Unit Side A ...