4M-1 OM
SHARP
SERVICE MANUAL
LCD COLOUR TELEVISION
MODEL
4M-IOM
In the interests of user-safety (Required by safety regulations in some countries ) the set should be
restored to its original condition and only parts identical to those specified should be used.
/
f
CONTENTS
Page
l
IMPORTANT SERVICE SAFETY PRECAUTION
. . . . . . . . . . . . . . . . . . . . . . . . . .
2
l
ELECTRICAL SPECIFICATIONS
. . . m . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3
l
LOCATION AND IDENTIFICATION OF CONTROLS
. . . . . . . . . . . . . . . . . . . . . .
4
l DISASSEMBLY AND REASSEMBLY
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5
l
TROUBLE SHOOTING TABLE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . a.. . . . .
6
l
ADJUSTMENT PROCEDURES
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
8
l
CHASSIS LAYOUT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
11
l
SCHEMATIC DIAGRAM AND WAVEFORMS
. . . . . . . . . . . . . . . . . . . . . . . . . .
13
l
PRINTED WIRING BOARD ASSEMBLIES
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
19
. BLOCK DIAGRAM
25
0 REPLACEMENTPARfSCI;S”::::::::::::::::::::::::::::::::::::::::
27
. PACKING OF THE SET
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
37
SHARP CORPORATION
4M-1 OM
IMPORTANT SERVICE SAFETY PRECAUTION
n Service work should be performed only by qualified service technicians who are
thoroughly familiar with all safety checks and servicing guidelines which follow:
WARNING
1.
For continued safety, no modification of any
circuit should be attempted.
2.
Disconnect AC power before servicing.
Any reading of
0.3
volt
RMS
(this corresponds
to
0.2
milliamp. AC.) or more is excessive and
indicates a potential shock hazard which must
be corrected before returning the receiver to
the owner.
BEFORE RETURNING THE RECEIVER
(Fire &Shock Hazard)
Before returning the receiver to the user,
perform the following safety checks:
1.
Inspect all lead dress to make certain that leads
are not pinched, and check that hardware is
not lodged between the chassis and other
metal parts in the receiver.
2.
Inspect all protective devices such as non-
metallic control knobs, insulating materials,
cabinet backs, adjustment and compartment
covers or shields, isolation resistor-capacity
networks, mechanical insulators, etc.
3.
To be sure that no shock hazard exists, check
for current leakage in the following manner.
Plug the AC Adaptor directly into a
110-240
volt AC outlet, (Do not use an isolation
transformer for this test).
Using two clip leads, connect a
1.5k
ohm,
10
watt resistor paralleled by a
0.15~.1F
capacitor in
series with all exposed metal cabinet parts and
a known earth ground, such as electrical
conduit or electrical ground connected to an
earth ground.
Use an AC voltmeter having with
5000
ohm per
volt, or higher, sensitivity to measure the AC
voltage drop across the resistor.
Connect the resistor connection to all exposed
metal parts having a return path to the chassis
(antenna, metal cabinet, screw heads, knobs
and control shafts, escutcheon, etc.) and
measure the AC voltage drop across the
resistor.
All checks must be repeated with the AC
Adaptor plug connection reversed.
(If
necessary, a nonpolarized adapter plug must
be used only for the purpose of completing
these checks.)
I
AC
I
TO EXPOSED’
CONNECT TO
METAL PARTS
KNOWN EARTH
GROUND
SAFETY NOTICE
Many electrical and mechanical parts in television
receivers have special
safety-related
characteristics.
‘These characteristics are often not evident from
visual inspection, nor can protection afforded by
them be necessarily increased by using
replacement components rated for higher
voltage, wattage, etc.
Replacement parts which have these special
safety characteristics are identified in this
manual; electrical components having such
features are identified by H A“ and shaded areas
in the Replacement Parts Lists and Schematic
Diagrams.
For continued protection,
replacement parts must be identical to those used
in the original circuit.
The use of a substitute
replacement parts which do not have the same
safety characteristics as the factory recommended
replacement parts shown in this service manual,
may create shock, fire, or other hazards.
4M-1 OM
ELECTRICAL SPECIFICATIONS
Model
Type
TV screen
Screen Size
LCD Panels
Drive method
Number of pixels
Receiving frequency
Audio output
Speaker
Light source
Terminals
Power supply
Power consumption
Dimensions (W x H x D)
Weigh
Supplied Accessories
AC Adaptor (1)
4M-10M
LCD
Colour
TV
4” (6.2 x
8.2cm/diagonal 10.3cm)
Transmission TN LCD panel
TFT
(Thin Film Transistor) active matrix system
37,440
(117
x 320)
VHF:
48.25-294.25MHz
UHF:
471.25~855.25MHz
200 mW
2.8cm
round type x 1
Fluorescent light tube, built-in(cold cathord type)
External power supply (DC
12V),
External antenna jack,
Earphone jack,
A/V
Input jack, Driver output jack
AC 110~240V 50/60Hz (AC adaptor supplied)
When using AC adaptor: Approx. 11 W (AC)
15.9x11.1 x 5.5cm
Approx. 570g (not including Set Stand)
AC Adaptor (1), Earphone (1), Antenna Adaptor (1), Adaptor
Socket plug(1)
Earphone (1)
Antenna Adaptor (1)
Adaptor Socket Plug (1)
Specifications are subject to change without notice
3
4M-10M
LOCATION AND
INDENTIFICATION
OF CONTROLS
External antenna socket
Speaker
AN input
Diversity socket
Earphone jack
Video input indicator
Tint control
Colour control
Colour/Sound AUTO indicator
Mounting socket
Channel
VIA
buttons
Channel Number Recall button
Power switch
Mode switch
Set Memory button
System switch
12V
DC power socket
Volume V / A buttons
Brightness V / A buttons
System change button
Rod antenna
Set stand
I LCD screen panel
4
4M-I OM
DISASSEMBLY AND REASSEMBLY
Remove the 7 rear cover fastening screws.
Remove the light guide fastening screws.
Undo the 3 light guide hooks.
Remove the 4 LCD holder fastening screws.
Remove the 4 Tuner
PWB
fastening screws.
5
TROUBLE SHOOTING TABLE
(Continued)
Prior checks:
TROUBLE SHOOTING TABLE
f
I
s
3
NEITHER IMAGE NOR SOUND COMES OUT
Yes
Are voltages applied at
BL, BL
and UB terminals
of tuner (corresponding
Is fuse
F701
normally functioning
7
D
No
Replace fuse
F701.
Fuse
F701
easily blows out.
1
Check the peripheral parts of 5701 and
T701
as well as the secondary load of
T701
for a short-circuit.
Are the secondary outputs ( +
5V. -8V,
+
13V,
-21V
and + 33V ) of
T701
all normal?
I
No
h
No
Check
L703
and
L704.
primary oscillation
circuit of T701.
QI
Push the CH
UPlDN
buttons in search
mode. Does the
BT
voltage at pin (4) of
tuner change?
Does the voltage go
up as the channel
1
,
numbers go up ?
I
Check the
AGC
IC201
and their
Continued to the following pages
I
#
Yes
Are the voltages of
Q861,Q862
and
4863
normal?
I
I
No
Yes
1
Are the voltages at
Are the voltages at
LClOand
LCll of
pins
(16)
(19) and (30)
CN803
normal?
of
IC802
normal ?
I
No
Check
C107, R523, R501, C501
and their peripheral parts, as well
as the Pin (20) line of IC 401.
TROUBLE SHOOTING TABLE
(Continued)
TROUBLE SHOOTING TABLE
(Continued)
Prior checks:
NO SOUND IS HEARD
ADJUSTMENT PROCEDURES ADJUSTMENT PROCEDURES
(Continued )
I
Adjusting Conditions
l
SIF
ADJUSTMENT : 1301
Adjusting Procedures
1. Feed colour bar signal.
(Set the input field strength to 58dBp)
2. Connect a the DC voltage meter to
TP205.
1. Adjust
L301
so that the voltage at TP205 be
1.42O.lV.
I
Adjusting Conditions Adjusting Procedures
. + B ADJUSTMENT :
VR701
1. Connect the DC voltage meter to
TP701.
1. Adjust
VR701
so that the + 5V line becomes
5 f 0.05v.
l
LLD
ADJUSTMENT : L209
1. Feed sweep signal to
TP20 I.
2. Add fixed bias to
TP202
(Pin (1) of IC201)
I
1. Adjust 1209 to make the
38.9MHz
marker as low
as possible.
I
l
SIGN POSlTlON ADJUSTMENT :
VR401
(0.5V-1 .OV
and
2.OV)
3. Connect an oscilloscope to
TP203.
1. Using the
CH-CALL
button, make
“20-20”
on
screen.
2. Adjust
VR401
to
position the “20-20” sign as
1. Feed colour bar signal.
(Set the input field strength to 58dBp)
2. Set the MODE switch 5401 to MEMORY (0)
position.
l
AFT ADJUSTMENT : L210
---A
,+-
i
9flmm
20-20’
1. Feed IF sweep signal to TPl 01.
2. Add fixed bias to
TP202.
3. Connect the oscilloscope to
TP204.
1. Adjust
L210
so that the
38.9MHr
marker be
positioned as shown below.
00
l
SIGN ADJUSTMENT : VR501
.
RF-AGC
ADJUSTMENT :
VR201
1. Set the MODE switch 5401 to SEARCH
(HI)
position.
2. Connect a diode and lk ohm resistor between
pins (16) and (33) of
IC401.
Set the unit to
MANUAL SEARCH mode.
1. Using the UP/DOWN key (A ,
v),
set the channel
bar at the leftmost end of the VHF sign (just
before changing to the UHF sign).
See the figure below.
1. Feed colour bar signal.
(Set the input field strength to 58
dBp)
2. Check the below
Colour mode : PAL
Sound mode : AUTO
1. Adjust
VR201
so that the voltage at
TPlO2
be
3
?O.lV.
r-Channel
bar
. AFT FINE ADJUSTMENT :
L210
1. Apply the output from the SG (Signal Generator)
to the TPlOl.
(Output from SG : 38.9MHz
(CW) 100dBp)
1. With the tuning in UP search mode, adjust
L210
so
that the voltage at
TP204
be 2.25V.
-
lk
ohm
3. Connect pin (24) of
lC501
to the + 5V line and cut
off the AFT.
2. Adjust
VR501
so that the tuner’s BT voltage at pin
(4) be 0.2V f O.lV.
ADJUSTMENT PROCEDURES
(Continued)
I
Adjusting Conditions
I
Adiustino Procedures
I
l
PAL CHROMA (1 H DELAY) ADJUSTMENT : VR803,
L807
1.
Feed PAL colour bar signal.
2.
Connect an oscilloscope to
TPB03,
TP802 (pin (43)
and (45) of IC801) with a resistor, one for each, in
between.
3.
Short-circuit
R806
to cut off the Y signal.
.
SECAM
ADJUSTMENT : BELL FILTER
T801
1.
Feed
SECAM
colour bar signal.
2.
Connect the oscilloscope to
TP804
(pin
(24)
of
IC801).
0 Probe: Below
3OpF,
Over 1
OMeg
ohms.
1
1.
Turn the
colour
control to make the biggest
difference between the green and magenta
levels.
2.
Adjust
VR803
and
L807
to obtain the waveform
shown at bottom.
Waveform before adjustment
Waveform after adjustment
I. Adjust
T801
so that the R and B levels be the
same.
t
To be at the same level
9
ADJUSTMENT PROCEDURES
(Continued )
I
Adjusting Conditions
Adjusting Procedures
I
.
SECAM
KILLER ADJUSTMENT :
L811
1.
Feed
SECAM
colour bar signal.
1.
Adjust
LB1
1 so that the DC level at pin
(19)
be
2.
Connect the oscilloscope to
TP805
(pin
(29)
of
maximum.
ICBOl).
c
l
SECAM
DEMODULATION ADJUSTMENT :
L812, L813
I.
Feed
SECAM colour
bar signal through the AV
jack.
I. Connect the oscilloscope to
TP801
and
TP803.
(2
Channels)
L
Cut off the Y component of the colour bar signal.
1.
Turn up the colour control all the way.
l
VIDEO OUTPUT ADJUSTMENT : VR802
1.
Feed
NTSC colour
bar signal.
2.
Turn on the colour killer to turn off colour.
(Connect
TP805
to
GND)
3.
Connect the oscilloscope to
TP801
(pin
(44)
of
lC801).
. SUB BRIGHTNESS ADJUSTMENT : VR813
1.
Feed
NTSC
colour bar signal.
2.
Turn on the colour killer to cut off
colour.
(Connect
TP805
to
GND)
3.
Set the brightness control in middle position.
4.
Connect the oscilloscope to
TPB07.
I. Adjust
LB12
(B-Y) and
L813
(R-Y) so that the DC
level of R-Y and
B-Y signals be -40 mV.
40mV
40mV
1.
Adjust VR802 so that the white level be
0.7v f
0.2v.
1.
Adjust VR813 so that the amplitude be 6V + 0.2V.
q-p-q)
ADJUSTMENT PROCEDURES
(Continued
)
Adjusting Conditions
I
Adjusting Procedures
0
CONTRAST ADJUSTMENT :
VR811
1.
Take the standard settings.
Set the brightness
1.
Adjust
VR811
so that the white level be 4V + 0.2V.
control to middle position.
2.
Feed
NTSC
colour bar signal through the AV jack.
3.
Turn on the colour killer to turn off
colour.
[Standard settings]
2.
Press the ” + ” side of BRIGHT and VOLUME keys.
3.
Connect the oscilloscope to
TP807.
:QfJJ,j+
1.
Press the MEMORY,
CH-CALL
and MEMORY keys
in this order.
. R-WHITE BALANCE ADJUSTMENT : VR810, VR812
1.
Feed monoscope pattern signal through the AV
1.
Turn
VR810
and
VRB12
until the peak-to-peak
jack.
amplitude of the waveform on the oscilloscope
2.
Set the brightness control to middle position.
screen becomes minimum.
3.
Connect the oscilloscope to
TP807 (G
-out).
(CH-1)
4.
Connect the
CH-2
cable of the oscilloscope to
TP808. (Oscilloscope in ADD mode)
5.
Invert the waveform of
channel-2
and add the
signal of channel-l to the channel-2.
. B-WHITE BALANCE ADJUSTMENT : VR807, VR806
1.
Feed monoscope pattern signal through the AV
jack.
2.
Set the brightness control to middle position.
3.
Connect the oscilloscope to
TP807
(G-out) (Cl-t-l).
4.
Connect the
CH-2
cable of the oscilloscope to
TP806. (Oscilloscope in ADD mode)
5.
Invert the waveform of
channel-2
and add the
signal of channel-l to the
channel-2.
1.
Turn
VR807
and
VR806
until the peak-to-peak
amplitude of the waveform on the oscilloscope
screen becomes minimum.
. COUNTER ELECTRODE BIAS ADJUSTMENT : VR814
1.
Feed 1 O-tone black-and-white pattern signal.
2.
Set the brightness control to middle position.
1.
Turn
VRB14
until the contrast gets sharpest.
l
SUB-BRIGHTNESS ADJUSTMENT : VR813
1 1.
Feed lo-tone black-and-white pattern signal.
12.
Set the brightness control to middle position.
1 1.
Turn
VR813
until the second tone on the scale
gets whitish on the screen.
4M-1 OM
4N
CHASSIS LAYOUT
SYSTEM
BRIGHT
SW BRlGKi
m
CHnNNEL
CHAMEL
CWEL
CHANGE SW
s
up
Efhw
Es?,
SELECT
SW
SW4 10
s.409 OWN
LP
SELECT SW
303
SAOC
GE
SZ5
E%
5701
FCMR
5WITcH
U
EB
Jr
(Component Side)
NE0
1
1H DELAY
DLB02
Le.12
L813
SEW
CN40
1
(oi
DECCOER
ioi
zEi%R
LED
(A/V)
•l
LB07
lti-EL”’ n EELA’
JZO I
TBOl
AV INPUT JACK
B”E%LTER
-u
CN701
FL(H)
SPOl
CtikCOE
0
SELECT
SW
0
0 0
F702 O.SA
5402
LEhCRYW
VR701
DC 5V
ADJ
F701 t
2%
SW41
1
SYSTEM
J202
DIVERSITY JACK
SECAM KILLEQ
CN 803
J30
I
LCD MODULE
EARPHONE JACK
ia
L-
1
CN703
BATTAQY
134
. TUNER
PWB
SELECT SW
1
J701
PCmER %@PLY
JACK
0
TU
101 TUNER
EC-Pa-2773
x201
SAW FILTER
I
J
1 I
2
I
3
1
4
I
5
I
6
I
11
10M
AIN PWB
0
VR601
S&J POSITION
•l
(Wiring Side)
0
7
0
BB
-
0
/
. LED
PWB
0408
LED A/V
O
(GREEN)
0407
LED AUTO
‘I-
0
0
7
I
8
I
9
I
10
I
11
I
12
I
12
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