Sharp LC-15M4E (serv.man8) Service Manual ▷ View online
21
LC-15M4E
TROUBLE SHOOTING TABLE
(Continued)
No sound
fr
om fr
ont
speaker
s
Yes
No
Is pin (53) of
IC2001 at
“L
”?
No sound
fr
om rear
speaker
s
Chec
k all the settings on the microprocessor’
s adjust process men
u.
No sound
No
Are outputs at
pins (1) and (7)
of IC903 as
specified?
Yes
No
Are inputs and
outputs of
IC303 as
specified?
Yes
No
Are inputs at
pins (5) and (8)
as w
ell as
outputs at pins
(2) and (11), all
of IC301, as
specified?
Muting eff
ect is
on.
Chec
k the
FSMU line
.
Chec
k IC901,
IC903 and their
per
ipher
al
par
ts
.
Chec
k IC303
and its
per
ipher
al
par
ts
.
Chec
k the line
in question,
IC303 and its
per
ipher
al
par
ts
.
Yes
Chec
k the
speak
ers and
their per
ipher
al
par
ts
.
No sound
fr
om
headphone
Yes
No
Is pin (55) of
IC2001 at
“L
”?
Chec
k the
headphone and
its per
ipher
al
par
ts
.
Chec
k Q371,
J4310 and their
per
ipher
al
par
ts
.
Yes
No
Is pin (54) of
IC2001 at
“L
”?
No
Are input at pin
(5) as w
ell as
output at pin
(2) of IC302, as
specified?
Yes
Chec
k the
speak
er and its
per
ipher
al
par
ts
.
Chec
k the line
IC901, IC303
and their
per
ipher
al
par
ts
.
Muting eff
ect is
on.
Chec
k the
FSMU line
.
No sound
fr
om output
line
Yes
No
Is pin (52) of
IC2001 at
“L
”?
No
Are outputs at
pins (1) and (7)
of IC902 as
specified?
Yes
Chec
k the line
in question.
Chec
k the
LMUTE line
.
Chec
k IC902
and its
per
ipher
al
par
ts
.
23
22
LC-15M4E
12
11
10
9
8
7
6
5
4
3
2
1
A
B
C
D
E
F
G
H
CHASSIS LAYOUT
OPERATION Unit
TERMINAL Unit
R/C RECEIVER Unit
MAIN Unit (Side A)
MAIN Unit (Side B)
25
24
LC-15M4E
12
11
10
9
8
7
6
5
4
3
2
1
A
B
C
D
E
F
G
H
BLOCK DIAGRAM
VIDEO IN
AUDIO L/R IN
PY IN
AV1
IN
POWER IN
DC 12C
DC 12C
VIDEO IN/OUT
AUDIO L/R
J4401
J4303
J4403
PB IN
J4404
J4404
PR IN
J4405
J4405
IN/OUT
AV2
IN/OUT
J4402
J4302
MSP
MUTE
MUTE
VPC
BUFFER
IN/OUT
SELECTOR
IC351
SELECTOR
IC351
IC902
IC901
HEAD PHONE
J4301
J4701
LPF
L/R
AUDIO AMP
REVERSE
FRONT SP
REAR SP
AUDIO AMP
AUDIO AMP
FRONT SP
FRONT SP
REAR SP
PY.PB.PR
AV1
VIDEOSELECTOR
IC402
I2C
LCD
CONTROLLER
IC1201
CONTROLLER
IC1201
FIFO
IC1202
IC1202
Y/C
CLOCK.H/VSYNC.FIELD
LCD
PANEL
R.G.B CONTROL SIGNAL
IC1102
IC1103
IC1104
IC1105
IC1106
IC1107
IC1108
IC1103
IC1104
IC1105
IC1106
IC1107
IC1108
IC1109
IC1110
GRADUATION
POWER FOR
LCD
POWER FOR
LCD
COMMON
DAC
IC1101
MPU
IC2001
I2C
CONTROL SIGNAL
SYNC
SEPARATION
SEPARATION
VOUT
IC801
SYNC
75ohm
BUFFER
Q453
Q454
Q454
AGND
IN/OUT
E2PROM
IC2004
IC2004
RESET
IC2002
IC2002
5V Reg
IC2701
IC2701
5V
IC701
PWM
DC/DC
TRANS
T701
5V
38V
16V
9V
-8V
3.3V Reg
IC781
IC781
3.3V
29V
8V
Q704
Q7306
IC702
LAMP
DC/AC
TRANS
TRANS
T1771
T1772
T1772
INVERTER
DRIVE
TR
DRIVE
TR
Q1771
Q1772
Q1772
LAMP
CHECK
CHECK
LAMP GND
DC12V
R/C
RECEIVER
CONTROL
KEY
BRIGHTNESS
PULS
IC903
IC302
IC301
IC303
IC401
R/C PWB
OPERATION PWB
TERMINAL PWB
MAIN PWB
LCD UNIT
I2C
CONTROL SIGNAL
QCNW-A036WJZZ
QCNW-A037WJZZ
QCNW-A038WJZZ
QCNW-
A039WJZZ
QCNW-5556CEZZ
QCNW-5557CEZZ
FFC
FFC
FFC
WIRE
WIRE
WIRE
WIRE
QCNW-4942CEZZ
QCNW-4942CEZZ
PWB GND
PWB GND
WIRE QCNW-A311WJZZ
WIRE QCNW-A312WJZZ
PWB GND
PANEL SHIELD
PANEL SHIELD
CN
CN
26
LC-15M4E
VOLTAGE MEASUREMENT CONDITION:
1. Voltages at test points are measured at the
supply voltage of AC 120V. Signals are fed by a
color bar signal generator for servicing purpose and
the above voltages are measured with a 20k ohm/
V tester.
color bar signal generator for servicing purpose and
the above voltages are measured with a 20k ohm/
V tester.
WAVEFORM MEASUREMENT CONDI-
TION:
TION:
1. Waveforms at test points are observed at the supply
voltage of AC 120V. Signals are fed by a color bar
signal generator for servicing purpose.
signal generator for servicing purpose.
INDICATION OF RESISTOR & CAPACI-
TOR:
TOR:
RESISTOR
1. The unit of resistance “
1. The unit of resistance “
Ω
” is omitted.
(K=k
Ω
=1000
Ω
, M=M
Ω
).
2. All resistors are ± 5%, unless otherwise noted.
(J= ± 5%, F= ± 1%, D= ± 0.5%)
3. All resistors are 1/10W, unless otherwise noted.
4. All resistors are Carbon type, unless otherwise
4. All resistors are Carbon type, unless otherwise
noted.
C
: Solid
W
: Cement
S
: Oxide Film
T
: Special
N
: Metal Coating
CAPACITOR
1. All capacitors are
1. All capacitors are
µ
F, unless otherwise noted.
(P=pF=
µµ
F).
2. All capacitors are 50V, unless otherwise noted.
3. All capacitors are Ceramic type, unless otherwise
3. All capacitors are Ceramic type, unless otherwise
noted.
(ML): Mylar
(TA): Tantalum
(PF): Polypro Film
(ST): Styrol
CAUTION:
This circuit diagram is original one, therefore there may be a
slight difference from yours.
slight difference from yours.
SAFETY NOTES:
1. DISCONNECT THE AC PLUG FROM THE AC
OUTLET BEFORE REPLACEING PARTS.
2. SEMICONDUCTOR HEAT SINKS SHOULD BE
REGARDED AS POTENTIAL SHOCK HAZARDS
WHEN THE CHASSIS IS OPERATING.
WHEN THE CHASSIS IS OPERATING.
IMPORTANT SAFETY NOTICE:
PARTS MARKED WITH “
å
” (
) A R E
IMPORTANT FOR MAINTAINING THE SAFETY OF
THE SET. BE SURE TO REPLACE THESE PARTS
WITH SPECIFIED ONES FOR MAINTAINING THE
SAFETY AND PERFORMANCE OF THE SET.
THE SET. BE SURE TO REPLACE THESE PARTS
WITH SPECIFIED ONES FOR MAINTAINING THE
SAFETY AND PERFORMANCE OF THE SET.
DESCRIPTION OF SCHEMATIC DIAGRAM
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