Read Sharp 76GF-64H (serv.man3) Service Manual online
1
76GF-64H
MODEL
76GF-64H
SHARP CORPORATION
CONTENTS
ELECTRICAL SPECIFICATION.......................2
IMPORTANT SERVICE NOTES.......................3
PRINTED WIRING BOARDS............................7
BLOCK DIAGRAM..........................................25
PART LIST......................................................26
PART LIST......................................................26
PAL I
SYSTEM COLOUR TELEVISION
SE
JB
76GF64H00
DA-50W
CHASSIS
SERVICE MANUAL
In the interests of user safety (required by safety
regulations in some countries) the set should restored
to its original condition and only parts identical to
those specified should be used.
regulations in some countries) the set should restored
to its original condition and only parts identical to
those specified should be used.
Issued: 22th Sep ‘00
SERVICE ADJUSTEMENTS.............................4
SCHEMATIC DIAGRAM.................................15
DOLBY SURROUND
PRO
LOGIC
2
76GF-64H
ELECTRICAL SPECIFICATIONS
•Power Input .......................220V-240 Volts AC 50Hz
•Power Consumption
•Audio Power Output Rating
Speakers
Left / Right........................................ 6 x 12cm
Centre.............................................. 6 x 12cm
Sub-Woofer................................11 cm Round
Centre.............................................. 6 x 12cm
Sub-Woofer................................11 cm Round
•Aerial Input Impedance
•Tuning Ranges..............45.75MHz thru 855.25 MHz
•Intermediate frequency.............................
.38.9MHz
•Adjacent Sound Carrier Trap
..................40.9MHz
•Sound Carrier Trap
...............................32.9MHz
VHF/UHF...........................75 ohm Unbalanced
CATV Special Channels
Normal Operating..................................105W
Stand-by Operating...................................1W
Internal Left Speaker.....................10W (MPO)
Internal Right Speaker..................10W (MPO)
Internal Centre Speaker...........10W (MPO)
External Front...................20W + 20W (MPO)
Sub-Woofer......................................20 (MPO)
Surround Speakers...............7W + 7W (MPO)
Internal Sub-Woofer.....................20W (MPO)
Internal Right Speaker..................10W (MPO)
Internal Centre Speaker...........10W (MPO)
External Front...................20W + 20W (MPO)
Sub-Woofer......................................20 (MPO)
Surround Speakers...............7W + 7W (MPO)
Internal Sub-Woofer.....................20W (MPO)
•White Level
Set brightness control to get total picture tube cathode current of 600 milliamperes under no signal condition.
Maximum necessary correction of each picture tube cathode current to get 8900 degrees K-20 MPCD screen
temperature should not exceed 15% of its original value.
X=0.290 Y=0.284
Maximum necessary correction of each picture tube cathode current to get 8900 degrees K-20 MPCD screen
temperature should not exceed 15% of its original value.
X=0.290 Y=0.284
WARNING
The chassis in this receiver is partially hot. Use an isolation transformer between the line
cord plug and power receptable, when servicing this chassis.
To prevent electric shock, do not remove cover. No user-serviceable parts inside. Refer
servicing to qualified sercice personnel.
cord plug and power receptable, when servicing this chassis.
To prevent electric shock, do not remove cover. No user-serviceable parts inside. Refer
servicing to qualified sercice personnel.
Convergence.........................Self Converging System
Focus....................................Bi-Potencial Electrostatic
Sweep Deflection...........................................Magnetic
•Adjacent Picture Carrier Trap
................30.9MHz
Specifictions are subject to change without prior notice.
3
76GF-64H
IMPORTANT SERVICE NOTES
SERVICING OF HIGH VOLTAGE SYSTEM AND PICTURE TUBE
Maintenance and repair of this receiver should be done by qualified service personnel only.
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 test probe) between picture tube ground tag and
high voltage lead. (AC line cord should be disconnected from AC outlet).
resistor in series with an insulated wire (such as test probe) between picture tube ground tag and
high voltage lead. (AC line cord should be disconnected from AC outlet).
1. Picture tube this receiver employs Integral Implosion protection.
2. Replace with tube of the same type number for continued safety.
3. Do not lift picture tube by the neck.
4. Handle the picture tube only when wearing shatterproof goggles and after discharging the high
voltage completely.
2. Replace with tube of the same type number for continued safety.
3. Do not lift picture tube by the neck.
4. Handle the picture tube only when wearing shatterproof goggles and after discharging the high
voltage completely.
X-RAY
This receiver is designed so that any X-Ray radiation is kept to an absolute minimum. Since certain
malfunctions are servicing may produce potentially hazardous radiation with prolonged exposure at
close range, the following precautions should be observed:
malfunctions are servicing may produce potentially hazardous radiation with prolonged exposure at
close range, the following precautions should be observed:
1. When repairing the circuit, be sure not to increase the high voltage to more than 33 KV, (at beam
1600
1600
µΑ) for the set.
2. To keep the set in a normal operation, be sure to make it function on 32KV
±
1KV (at beam 1600
µΑ)
in the case of the set. The set has been factory - adjusted to the above mentioned high voltage. If
there is a possibility that high voltage fluctuates as a result of the repairs, never forget to check for
such high voltage after the work.
3. Do not substitute a picture tube with unauthorized types and/or brands which may cause excess
X-Ray radiation.
there is a possibility that high voltage fluctuates as a result of the repairs, never forget to check for
such high voltage after the work.
3. Do not substitute a picture tube with unauthorized types and/or brands which may cause excess
X-Ray radiation.
BEFORE RETURNING THE RECEIVER
In addition to the checks necessary as a result of a repair having been carried out, the following
additional safety checks should also be made before returning the units to the user.
additional safety checks should also be made before returning the units to the user.
1. Inspect all lead dress to make certain that leads are not pinched or that hardware is not logged
between the chassis and other metal parts in the receiver.
2. Inspect all protective devices such as non-metallic control knobs, insulating fish papers, cabinet
backs, adjustment and compartment covers or shields, insolation resistor-capacity networks,
mechanical insulators etc.
between the chassis and other metal parts in the receiver.
2. Inspect all protective devices such as non-metallic control knobs, insulating fish papers, cabinet
backs, adjustment and compartment covers or shields, insolation resistor-capacity networks,
mechanical insulators etc.
4
76GF-64H
SERVICE ADJUSTMENTS
All the adjustments required for this chassis will be done in Service Mode, except G2 and Focus.
••••• G2 ADJUSTMENT
1.Receive cross hatch pattern signal.
2. Set contrast to 80/100 and brightness to 40/100.
3. Connect the oscilloscope to the red cathode and adjsust G2 to read
140V on the sensor pulse as in the drawing:
2. Set contrast to 80/100 and brightness to 40/100.
3. Connect the oscilloscope to the red cathode and adjsust G2 to read
140V on the sensor pulse as in the drawing:
NOTE:
Oscilloscope should be adjusted for vertical TV field trigger and synchronized
with wideo signal.
Oscilloscope should be adjusted for vertical TV field trigger and synchronized
with wideo signal.
••••• SERVICE MODE FUNCTION
This mode function is provided to assist with the settings of those adjustments that may vary from one
Picture Tube to another, or between models.
Picture Tube to another, or between models.
In order to use the Service Mode:
1. Connect Test Pattern signal to antenna terminal.
2. Press main switch to «OFF».
3. Press volume-down and channel-up buttons and
main switch to «ON» simultaneously.
4. Service mode is now entered.
2. Press main switch to «OFF».
3. Press volume-down and channel-up buttons and
main switch to «ON» simultaneously.
4. Service mode is now entered.
The required adjustments can then be made from the Remote Control Unit.
The only buttons required are the following:
Up/Down-channel for movement in adjustment options menu; Up/Down-volume are used to carry out an
adjustment in said menu; ON/OFF is used to memorize a new adjustment.
Adjustment menu is as follows:
The only buttons required are the following:
Up/Down-channel for movement in adjustment options menu; Up/Down-volume are used to carry out an
adjustment in said menu; ON/OFF is used to memorize a new adjustment.
Adjustment menu is as follows:
To exit service mode, press main switch ot OFF.
Adjustment menu is as follows:
Horizontal:
-Adjust HORIZONTAL SHIFT.
-Adjust E-W WIDTH.
-Adjust PIN PHASE.
-Adjust PIN AMPLITUDE.
-Adjust UPPER CORNER CORRECTION.
-Adjust LOWER CORNER CORRECTION.
-Adjust HORIZONTAL SHIFT.
-Adjust E-W WIDTH.
-Adjust PIN PHASE.
-Adjust PIN AMPLITUDE.
-Adjust UPPER CORNER CORRECTION.
-Adjust LOWER CORNER CORRECTION.
All adjustments for Geometries are based on internal pattern (fig.1)
The procedure for making adjustments is as follows:
The procedure for making adjustments is as follows:
Vertical:
-Adjust VERTICAL AMPLITUDE.
-Adjust S-CORRECTION.
-Adjust VERTICAL SHIFT.
-Adjust VERTICAL LINEARITY.
-Adjust VERTICAL AMPLITUDE.
-Adjust S-CORRECTION.
-Adjust VERTICAL SHIFT.
-Adjust VERTICAL LINEARITY.
Fig.1
CH
1
2
140 V
CH1 gnd
-RED CUT OFF.
-GREEN CUT OFF.
-BLUE CUT OFF.
-ALTER NVM PAGE.
-ALTER NVM POSITION.
-ALTER NVM VALUE.
-TELETEXT MIX MODE CONTRAST.
-TELETEXT CONTRAST.
-OSD CONTRAST.
-DVCO ADJUSTMENT (Only NTSC).
-DVCO ADJUSTMENT (Only PAL).
-AGC ADJUSTMENT.
-AFT ADJUSTMENT.
-OPC VALUE.
-AUTOINSTALLATION ON/OFF.
-GREEN CUT OFF.
-BLUE CUT OFF.
-ALTER NVM PAGE.
-ALTER NVM POSITION.
-ALTER NVM VALUE.
-TELETEXT MIX MODE CONTRAST.
-TELETEXT CONTRAST.
-OSD CONTRAST.
-DVCO ADJUSTMENT (Only NTSC).
-DVCO ADJUSTMENT (Only PAL).
-AGC ADJUSTMENT.
-AFT ADJUSTMENT.
-OPC VALUE.
-AUTOINSTALLATION ON/OFF.
-SERVICE SOFTWARE AND HEXADECIMAL
COUNTER DISPLAY: «SW ON XXXX SW OFF
XXXX HOURS ON XXXX
-HORIZONTAL SHIFT.
-EAST WEST WIDTH.
-PIN PHASE.
-PIN AMP.
-UPPER CORNER AMPLITUD.
-LOWER CORNER SYMETRY.
-VERTICAL LINEARITY.
-VERTICAL AMPLITUDE.
-S CORRECTION.
-VERTICAL SHIFT.
COUNTER DISPLAY: «SW ON XXXX SW OFF
XXXX HOURS ON XXXX
-HORIZONTAL SHIFT.
-EAST WEST WIDTH.
-PIN PHASE.
-PIN AMP.
-UPPER CORNER AMPLITUD.
-LOWER CORNER SYMETRY.
-VERTICAL LINEARITY.
-VERTICAL AMPLITUDE.
-S CORRECTION.
-VERTICAL SHIFT.
-RED GAIN.
-GREEN GAIN.
-BLUE GAIN.
-BLUE GAIN.
