Sharp Linytron C-1004G User manual

SHARP SERVICE MANUAL
SERVICE-ANLEITUNG
? SERVICE HANDBOK
| Ef fl Linyteon
PAL SYSTEM COLOUR TELEVISION
PAL SYSTEM FARBFERNSEHGERAT
FARG-TV MED PAL-SYSTEM
MODELS /MODELL. /MODELL.
C-1004G,S,N
ELECTRICAL SPECIFICATIONS
Aerial Input... 2. ee ee ee 75 ohm unbalanced Power [nputic-es ood. 6 Sek nes ae ae ah 220 volts AC 50 Hz
Convergence ........ cee eee Self Converging System 12 volts DC
FOGUS: <<. sseehclecehun woety Bb ee ee ee Bi-potential electrostatic Power Consumption ..........00 50584 e ae 42 Watt (at AC)
Audio Power Output Rating ..........005 0.6 Watt (max.) 37 Watt (at DC 12V)
Intermediate Freqnencies Speaker Size/ :
Picture IF Carrier Freqnency .............. 38.9 MHz Voice Coil Impedance .......... 4 x 8cm (8 ohm at 400 Hz)
Sound IF Carrier Freqnency ............24. 33.4 MHz Sweep Deflection... 2... 0... ee ee ee ees Magnetic
Colour Sub-Carrier Frequency ....... 40.4 MHz (Nominal) Tuning Range. .......... 00200 VHF-Channels 2 thru 12
UHF-Channels 21 thru 69
TECHNISCHE DATEN
Antenneneingangsimpedanz.........
75
Ohm
unausgeglichen
Stromversorgung
..
1...
6
ee ee
ee
220
Volt
Netzstrom
50
Hz
Konvergenz
..
2... 0...
ee
eee
Selbstkonvergierendes
System
42
Volt
Gteichstrom
Strahienbiindelung
..........--
Bi-potential
elektrostatishc
Leistungsaufnahme.
..........06.%
42
Watt
(bei
Netzstrom)
Tonausgangsleistung
.. 2...
2
ee
ee
es
0,6
Watt
{max.)
37
Watt
(bei
Gleichstrom)
Zwischenfrequenzen
Lautsprechergr68/
Bildzwischentragerfrequenz
........-.-..200%
38,9 MHz
Lautsprecherspulenimpedanz.....
4
x
8
cm
(8
Ohm
bei
400:Hz)
Tonzwischentragerfrequenz....
2.1...
2 eee eee
33,4
MHz
Abtastausschlag.
.
2...
ee
ee
es
Magnetisch
Farbuntertragerfrequenz
......:...
40,4
MHz
(nominal)
Abstimmbereich
.......0...-
002004
VHF
Kanile
2
bis
12
UHF Kandle 21 bis 69
ELEKTRISKA SPECIFIKATIONER
Antenninmatning.
.......002
2.220
75
ohm
obalancerad
Kraft
ineffekt.........0.0.,
BA
th
Segla
SR
B68,
MS
220
V
AC
50Hz
Konvergens
........020
08005
Sjalvkonvergerande
System
12V
DC
FOKUS:
hse i
veces oh
a
eh
Dubbelpotentiell
Elektrostatisk
Kraftférbrukning.
2.2...
ee
ee
ee eee
42
Watt
(vid
AC)
Audio
Kraftuteffekt
varde
..........-.45
0,6
Watt
(max)
:
37
Watt
(vid
DC)
Mellanliggande
frekvenser
Hégtalares
storlek/
Bild
IF
Barvagsfrekvens
.......-.-.-..000-
38,9
MHz
Réstspole
impedans
..........
4
x
8
cm
(8
ohm
vid
400
Hz)
Ljud
IF
Barvagsfrekvens
..
2...
ee
eee
eee
33,4
MHz
Avs6kningsavbéjning....
2...
.
eee
ee
ee
Magnetisk
Farg
Underbarvagsfrekvens
.........
40,4
MHz
(Nominell)
_
Avstamningsomrade
.......-...-
VHF
kanaler
2
genom
12
UHF kanaler 21 genom 69
C-1004G,S,N

Page
ELECTRICAL
SPECIFICATIONS
.........0.0..
1
CHASSIS
LAYOUT
DIAGRAM
.............
IMPORTANT
SERVICE
NOTES..........-.05.
3
PRINTED
WIRING
BOARD
ASSEMBLIES......
DESCRIPTION
OF
NEW
CIRCUIT
.............
4
SCHEMATIC
DIAGRAMS
AND
WAVEFORMS...
ADJUSTMENT
1.2.2...
0
cee
eee
ee
eee
eee
7
REPLACEMENT
PARTS
LIST
..............
TROUBLE SHOOTING TABLE ............-.--- 12
INHALT
Seite
TCHNISCHE
DATEN
.......
20:
ee
eee
ee
eee
i]
CHSISANORDNUNGSPLAN
...........
so
A
WICHTIGE
SERVICE-ANMERKUNGEN
.........
20
LEITERPLATTENEINHEITEN
.............
BESCHREIBUNG
DER
NEUEN
KREISES
........
21
SCHEMATISCHER
SCHALTPLAN
UND
EINSTELLUNGEN...
2...
00...
eee
ee
eee
24
WELLENFORMEN.........
00+.
e
eae
FEHLERSUCHTABELLE
............225
eee
29
ERSATZTEILLISTE...
2...
cc
ee
ee
ee
INNEHALL
Sid
ELEKTRISKA SPECIFIKATIONER ............ 1 FELSOKNINGSCHEMA ..........0 00+ eee
OBSERVERA
VID
SERVICEATGARD
..........
37
CHASSIPLANRITNING
........
000
eeu
eee
BESKRIVNING
AV
NYA
KRETSAR
...........
38
KRETSKORT
MED
KOPPLINGSSCHEMA......
JUSTERINGAR .. 0... 0. cee ee eee es 41 PRINCIPSCHEMAN OCH FREKVENSKURVOR. .
RESERVDELSBETECKNING ..........000.
WARNING
The
chassis
in
this
receiver
is
partially
hot.
Use
an
isolation
transformer
between
the
line
cord
plug
and
power
receptacle,
when
servicing
this
chassis.
To
prevent
electric
shock,
do
not
remove
cover.
No
user
—
serviceable
parts
inside.
Refer
servicing
to
qualified
service
personnel.
WARNUNG
Das
Chassis
dieses
Empfangsgerites
steht
teilweise
unter
hohen
Spannungen.
Bei
Wartungsarbeiten
an
diesem
Chassis
mu
deshalb
ein
Isolationstransformator
zwischen
dem
Netzkabelstecker
und
der
Steck-
dose
verwendet
werden.
Um
elektrische
Schlage
zu
vermeiden,
darf
das
Abdeckgehduse
nicht
entfernt
werden.
Im
Inneren
des
Gerites
befinden
sich
keine
vom
Benutzer
einstellbaren
Teile.
Wartung
und
Reparaturarbeiten
miissen
qualifiziertem
Service-Personal
tiberlassen
werden.
VARNING
Chassiytan
ar
delvis
het.
Anvand
alltsa
en
isoleringstransformator
mellan
vaxelstr6mskontakten
och
strémingangen
nar
nagot
servicearbete
skall
utféras
pa chassit.
Ta
inte
bort
chassiomhéljet
fér
fara
av
elektriska
sttar.
Forsék
aldrig
att
sjalv
utfGra
nagra
serviceatgarder
inne
i
apparaten
utan
vand
till
kvalificerad
personal.
Sid

IMPORTANT SERVICE NOTES
Maintenance and repair of this receiver should be done by
qualified service personnel only.
SERVICING OF HIGH VOLTAGE SYSTEM AND
PICTURE TUBE
When servicing the high voltage system, remove static
charge from it by connecting a 10k ohm Resistor in series
with an insulated wire (such as a test probe) between
picture tube dag and 2nd anode lead. (AC line cord should
be disconnected from AC outlet.)
1. Picture tube in this receiver employs integral implosion
protection.
2. Replace with tube of the same type number for continu-
ed safety.
3. Do not lift picture tube by the neck.
4. Handle the picture tube only when wearing shatter-proof
goggles and after discharging the high voltage com-
pletely.
X-RAY
This receiver is designed so that any X-ray radiation is kept
to an absolute minimum. Since certain malfunctions or
servicing may produce potentially hazardous radiation
with prolonged exposure at close range, the following pre-
cautions should be observed:
1. When repairing the circuit, be sure not to increase the
high voltage to more than 24.5kV, (at beam 470uA) for
the set.
. To keep the set in a normal operation, be sure to make
it function on 18.0kV + 2.0kV (at beam 470yA) in the
case of the set. The set has been factory - adjusted to
the above-mentioned high voltage.
’. If there is a possibility that the high voltage fluctuates
as a result of the repairs, never forget to check for
such high voltage after the work.
. Do not substitute a picture tube with unauthorized
types and/or brands which may cause excess X-ray
radiation.
BEFORE RETURNING THE RECEIVER
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 or that hardware is not lodged between the
chassis and other metal parts in the receiver.
. Inspect all protective devices such as non-metallic con-
trol knobs, insulating fishpapers, cabinet backs, adjust-
ment and compartment covers or shields, isolation
resistor-capacity networks, mechanical insulators etc.
I

DESCRIPTION OF NEW CIRCUIT
DC-DC Inverter Circuit
This model is provided with a DC-DC inverter circuit so
that it can be used outdoors operating on the automobile
battery (12V DC).
AC operation and DC operation are changed from each
other automatically by using the AC or DC power cord to
connect it to the set. ,
The DC-DC inverter circuit ensures not only to amplify the
output voltage but also to regulate the input voltage against
its fluctuation.
Fig. 1 is a block diagram of the DC-DC inverter circuit.
The square-wave signal which has been caused by the hori-
zontal oscillator circuit (IC501) is first applied to the integ-
ration circuit where it is converted to a sawtooth-wave
signal to be fed to the pulse-width converter circuit. In the
pulse-width converter circuit, the sawtooth-wave signal is
again converted into a square-wave signal then entering the
inverter drive circuit where it is amplified enough to drive
the inverter output circuit.
The output voltage from the inverter output circuit is set to
+115V DC, and it is applied to the error detection circuit
where it is compared with the reference voltage to control
the pulse-width converter circuit.
Fig. 2 shows what parts the inverter circuit is composed of
and Fig. 3 reveals the waveforms of the voltages which are
available at the points @ to ® in Fig. 2.
Coming from the horizontal oscillator circuit, the square-
wave voltage appears at the point @) and is integrated by
R779 and C775 so that it is converted into a triangular-
wave voltage as shown in Fig. 3-(B).
The triangular-wave voltage is applied to the base of Q2:
this transistor Q2 is biased to turn on only with the voltage
which is lower than the level indicated by the chained line
in Fig. 3-(B). Now that the triangular-wave voltage shown -
by the solid line in Fig. 3-(C) is applied to the base of Q2,
the transistor Q2 turns on only when it is given the voltage
Integra-
tion
circuit
indicated by the shaded area in Fig. 3-(B): as the result,
at the point © in Fig. 2 there appears the voltage having
the waveform indicated by the solid line in Fig. 3-(C).
Then the voltage is sent to Q3 where its waveform is in-
verted to be the one shown in Fig. 3-(D). The transistor
Q3 is to activate the drive transformer T770. Actually when
Q3 turns off, T771 is allowed to turn on to get the output
transistor Q770 in operation; the voltage caused at the
point © in Fig. 2 (at the base of Q770) has the waveform
as shown in Fig. 3-(E).
The
voltage
at
the
collector
of
Q770
has
the
waveform
as
shown
in
Fig.
3-(F)
while
the
current
there
of
has
the
waveform
as
shown
in
Fig.
3-(G).
The
output
voltage
from
the
inverter
transformer
is
applied
to
D775
where
it
is
rectified
as
long
as
Q770
is
turned
off:
that
is
to
say,
when
Q770
is
turned
on,
the
magnetic
energy
- at T771 increases so that the output voltage from D775
also increases.
The rectified output voltage is then sent to the succeeding
load circuit. However, a part of it is fed back to Q1 and
then to Q2 via ZD1 to control biasing of Q2.
Now suppose that there is a rise of the output voltage of
the
transformer
due
to
some
reasons
(e.g.
due
to
an
increase
of input DC voltage or an alleviation of the output load).
Then the current at the base of Q1 increases with its
collector’s current also increasing. Therefore the voltage at
the base of Q2 decreases and this means that the turn-on
time of Q2 becomes longer than before: the output wave-
form then caused refers to that indicated by the brokin line
in Fig. 3B). The output waveforms available thereafter
are those indicated by the broken lines in Fig. 3-(C), -(D),
4E), -(F) and (G): this fact is to shorten the turn- on time
of Q770 so as to decrease the magnetic energy charged in
T771. As the result, the output voltage from T771 which
has been higher than specified is now decreased to its
normal level.
Pulse width Inverter Inverter
converter drive output
circuit circuit circuit
Error
detector
circuit
'
OUT
DC 115V

___g
1C501
1XO065CE
+12V DC IN-PUT
Z0103CE
1771
rc
:
1770
1X0248CE
0000000
L771
+
C776
Voltage
waveform at
point @
ov
Voltage
waveform at
point ® 2 turn-on
level
Figure 2.
+115V DC OUT-PUT
Voltage
waveform at
point ©
Voltage
waveform at
point ©
Voltage
‘waveform at
point® ”°
Voltage
waveform at
point ©
Current
waveform at 2
collector of
Q770
eee Serene Lage
ro eats Be
Figure 3.
C780
|
|
|
|
|
|
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|
|
|
epee |

The DC-DC inverter circuit has two built-in functions for
its safer operation, which are described below.
(i) Overload preventive function
After passing through F770, the supply voltage (12V
DC) is separated into three currents i,, i, and i;. the
current i is applied to the output transistor Q770 to
make it ready to be in operation. The current i, is
sent via R651 to pin @) of IC5O1 so that 1501 is in
operation the output of which appears at the point @):
at the same time, the transistor Q2 turns on to cause
an output signal at its collector. Further the current i;
is applied via C774 to the primary side of T770 the
output of which is instantly impressed onto the base of
Q770. With Q770 turned on, there is an instant output
of DC voltage between pins @) and (5) of T771 which
is applied to D775 for the rectification. At the same
time, there is also an instant output of DC voltage bet-
ween pins and @) of T771 and is fed to D770 for
the rectification.
The output current from D770 is separated into two
currents i, and is: the former is sent via D773 and
R651 to IC5O1, and the latter to Q3.
Usually
the
rectification
DC
output
from
D770
is
about 18V, and since it is higher than the power
supply voltage (about 12 V), the voltage at the cathode
of D772 becomes higher than its anode so that this
diode D772 turns off.
However, if there occurs an overload at the output
circuit (due to its shortcircuit, for example), no voltage
is generated between pins and (6) of T771 so that
the inverter circuit gets in a stop automatically: at the
time, however, the oscillator circuit [501 is still in
operation since it is given i, from D772.
When the inverter circuit is stopped in this way, first
turn off the power switch to discharge C774, and
about 10 second thereafter, turn on the power switch
again to cause the inverter circuit to restart.
(ii) Input reverse-connection preventive function
The diode D771 is connected in parallel to the power
supply circuit (12V DC): actually, the cathode and
anode of the former are connected respectively to the
plus (+) terminal and minus (—) terminal of the latter.
With this design, the diode is usually kept turned off as
far as the input connection of the car battery cord is
made in a proper way.
But if the input connection with reverse polarity is
made as shown in Fig. 4, D771 turns on and F770 is
shorted to be blown out. With F770 blown out, the
inverter circuit gets in a stop not suffering any further
trouble.
Figure 5 shows the other way of connection in which a
diode is connected in series to the power supply circuit
(12V DC). With this design, the diode turns off, with the
fuse being not blown out, if the reverse connection of the
car battery cord is performed. With the diode turned off,
the inverter circuit stops its operation thus suffering no fur-
ther trouble. __
However,
this
design
has
such
a
drawback
that
the
diode
is
kept
turned
on
as
long
as
the
set
is
normally
operating:
this
refers
to
the
power
consumption
of
about
4.5W
needed
for
the
diode
to
operate.
To vaoid this unnecessary power consumption, this set
employs the protective circuit shown in Fig. 4 instead of
that shown in Fig. 5.
Inverter
circuit
Figure 4.
Inverter
circuit
Figure 5.

ADJUSTMENT
COLOUR PURITY ADJUSTMENT
For best results, it is recommended that the purity adjust-
ment be made in final receiver location. If the receiver will
be moved, perform this adjustment with it facing east. The
receiver must have been operating 15 minutes prior to this
procedure and the faceplate of the CRT must be at room
temperature. The receiver is equipped with an automatic
degaussing circuit. However, if the CRT shadow mask has
become excessively magnetized, it may be necessary to
degauss it with manual coil. Do not switch the coil OFF
while the raster shows any effect from the coil.
The following procedure is recommended while using a Dot
Generator.
1. Check for correct location of all neck components.
(See Figure 6.)
2. Rough-in the static convergence at the center of the
CRT, as explained in the static convergence procedure.
3. Rotate the picture control to centre of its rotation range
and rotate Brightness control to maximum CW position.
4. To obtain a blank raster, connect a short clip lead be-
tween pin 2 of IC801 and earth. Then, rotate screen
control CW until normal raster is obtained.
5. Rotate the Red Bias and Blue Bias controls to maximum
CCW position Rotate the Green bias control sufficiently
in a CW direction to produce a green raster.
6. Loosen the deflection yoke tilt adjustment wedges
(three), loosen the deflection yoke clamp screw and
push the deflection yoke as close as possible to the CRT
screen.
7, Begin the following adjustment with the tabs on the
round purity magnet rings set together, initially move
the tabs on the round purity magnet rings to the side of
the CRT neck. Then, slowly separate the two tabs while
_ at the same time rotating them to adjust for a uniform
green vertical band at the centre of the CRT screen.
8. Carefully slide the deflection yoke backward to achieve
green purity (uniform green screen).
NOTE: Center purity was obtained by adjusting the
tabs on the round purity magnet rings, outer edge
purity was obtained by sliding the deflection yoke
forward. Tighten the deflection yoke clamp screw.
9, Check for red and blue field purity by reducing the
output of the Green Bias control and alternately in-
creasing output of Red and Blue Bias controls and touch
up adjustments, if required.
10. Disconnect between pin @2 of IC801 and earth, if
connect in connect in step 4.
11. Perform BLACK AND WHITE TRACKING procedure.
STATIC (CENTER) CONVERGENCE ADJUSTMENT
1. Switch the Receiver ON and allow it to warm up for 15
minutes.
2. Connect the output of a Crosshatch Generator to the
Receiver and, concentrating on the centre of the CRT
screen, proceed as follows:
a. Locate the pair of 4 pole magnet rings. Rotate indi-
vidual rings (change spacing between tabs) to con-
verge the vertical red and blue lines. Rotate the
pair of rings (maintaining spacing between tabs) to
converge the horizontal red and blue lines.
b. After completing red and blue centre convergence,
locate the pair of 6 pole magnet rings. Rotate indi-
vidual rings (change spacing between tabs) to con-
verge the vertical red and blue (magenta) and green
lines. Rotate the pair of rings (maintaining spacing
between tabs) to converge the horizontal red and
blue (magenta) and green lines.
DEFLECTION YOKE PURITY MAGNETS
CLAMP SCREW
6 POLE CONV.
MAGNETS
L, POLE CONV,
MAGNETS
L DEFLECTION YOKE
TILT ADJUSTMENT WEDGE
| DEFLECTION YOKE
TAPE
Figure 6. Picture Tube Neck Components Location

DYNAMIC CONVERGENCE ADJUSTMENT
Dynamic convergence (convergence of the three colour
fields at the edges of the CRT screen) is accomplished by
proper insertion and positioning of three rubber wedges
between the edge of the deflection yoke and the funnel of
the CRT.
This is accomplished in the following manner.
1. Switch receiver ON and allow it to warm up for 15
minutes.
2. Apply crosshatch pattern from Dot/Bar Generator to
receiver. Observe spacing between lines around edges of
CRT screen.
3. Tilt the deflection yoke up and down, and insert tilt
adjustment wedges @) and @) between the deflection
yoke and the CRT until the mis-convergence illustrated
in Fig. 7 @ has been corrected.
4. Tilt the deflection yoke right and left, and insert tilt
adjustment wedge (3) between the deflection yoke and
the CRT until the mis-convergence illustrated in Fig. 7
® has been corrected.
5. Alternately change spacing between, and depth of in-
sertion of, the three wedges until proper dynamic con-
vergence is obtained.
6. Use a strong adhesive tape to firmly secure each of the
three rubber wedges to the funnel of the CRT.
7. Check purity and readjust, if necessary.
DEFLECTION YOKE REAR VIEW
Figure 7. Dynamic Convergence Adjustment

(1) Receive broadcast
signal through
extenal antenna.
TP601 «
tp6e02 « ©
Figure 8.
(1) Short TP601 and TP602.
(2) Adjust R607 to have almost proper
horizontal sync.
(3) Remove the shorting of TP601 and TP602.
| (1) Receive broadcast
signal through
external antenna.
LLL.
LLL SL LLL
LLL LLL
Figure 9.
(1) Fig. 9 (A):
If the black horizontal line moves down
slowly, turn V-hold knob counterclockwise
to have a proper sync.
Fig. 9 (B):
If several horizontal lines appear at random,
turn V-hold knob clockwise to have a proper
sync.
(1) Connect pattern generator
(PM5508) to the unit.
(2) Set antenna input
to about 70 dB.
(3) Set the pattern to
“GRAY SCALE”.
Contrast: MAX
Brightness: Set it
so that the black/
gray scale becomes
easy to see.
*Tuner AGC: Approx. 4V
Figure 10.
(1) Turning RF-AGC (R209) clockwise will
produce noise in picture,
(2) Turning RF-AGC (R209) counterclockwise
will remove such noise; but the picture,
then, moves a little to right and its
brightness somewhat lessens.
Then, for proper adjustment:
Turn RF-AGC fully clockwise to produce
noise, turn it back gently to remove the
noise and stop just at a point where no
phenomenon such as (2) arises.

No.
Where to adjust Setting
Adjustme nt
4 Chroma (I) (1) Connect pattern generator (1) Set the pattern to “MATRIX”.
(PM5508) to the unit, and (2) Adjust T801 to obtain uniform
set antenna input to about brightness — the same - for every
70 dB scanning line.
(2) Contrast: MAX (3) Set the pattern to “DELAY”.
Brightness: MIN (4) Adjust R804 to obtain uniform
Color: about 1/2 brightness — the same for every
scanning line.
(5) Set the pattern to “PHASE”
Adjust T802 to have — the same
color shading in both upper and
lower parts of picture.
Figure 11.
5 Picture tube (1) Connect pattern generator (1) Short TP401 and TP402.
(PM5508) to the unit.
(2) Set the pattern to “GRAY
SCALE”
(3) Contrast: MAX
Brightness: MAX
cut-off adjust
9 1404 ce
‘ [_]icso1
TP403
TP401
e
e | 1C201
TP402
TUNER
FBT
Figure 12.
R863 R857
(B-Drive) (G-Drive)
R853 (R-Bias)
R854 (G-Bias)
R865 (B-Bias)
Figure 13.
(2) Short TP403 and TP404.
(3) Set G-drive control (R357) and
B-drive control (R863) to abour “1/2”.
(4) Turn R-bias control (R853) G-bias
control R859) and B-bias control
(R865) counterclockwise to their
maximum extent.
(5) Turn screen control (R626), from its
minimum position, slowly clockwise to
make a slight horizontal line come into
existence, and stop it.
(6) Adjust the R853, R859 and R865
separately to make that horizontal
line equally colored for every color.
(R, G and B). However, if the color
appearing at first is, for instance, red
never touch the R853 but only the
R859 and R865 — the same holds true
for the colors green and blue when they
appear at first.
(7) Turn the screen control V.R clockwise
to vanish the horizontal line, and stop.