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SERVICE
MANUAL
CONTENTS
X-RAY RADIATION PRECAUTION...............................................................1
SAFETY PRECAUTION.............................................................................1
PRODUCT SAFETY NOTICE......................................................................2
INSTALLATION AND SERVICE ADJUSTMENTS.............................................3
GENERAL INSTRUCTION...........................................................................3
ALIGNMENT ITEMS AND PROCEDURE........................................................3
FACTORY ADJUSTMENT MODE..................................................................4
CHECKING POINT.......................................................................................5
PRESET THE FOLLOWING IN FACTORY.........................................................6
FACTORY MENU..........................................................................................6
CONVERGENCE MAGNET ASSEMBLY POSITIONING...................................8
COLOR PURITY ADJUSTMENT....................................................................8
CONVERGENCE ADJUSTMENT.....................................................................8
CENTER CONVERGENCE ADJUSTMENT ..................................................8
CIRCUMFERENCE CONVERGENCE ADJUSTMENT ...................................9
USA CHANNEL FREQUENCY TABLE (181 CH).............................................10
WIRING DIAGRAM..................................................................................12
BLOCK DIAGRAM....................................................................................13
IC BLOCK DIAGRAM................................................................................14
SCHEMATIC DIAGRAM............................................................................19
ELECTRICAL PARTS LIST........................................................................20
CAUTION: THIS SERVICE MANUAL IS ONLY FOR PROFESSIONAL SERVICE PERSONNEL'S
REFERENCE. BEFORE SERVICING THIS CHASSIS, PLEASE READ THE
FOLLOWING NOTICE ITEMS.
0
SAFETY INSTRUCTION
Before servicing and aligning this equipment, please read the following "X-RAY RADIATION
PRECAUTION" ,"SAFETY PRECAUTION" and "PRODUCT SAFETY NOTICE".
X-RAY RADIATION PRECAUTION
1 Excessive high voltage can produce potentially hazardous X-RAY RADIATION. To avoid such hazards,
the high voltage must not be above the specified limit. The normal value of the high voltage of this
receiver is 29 or 26.5kV(20") at zero beam current (minimum brightness) under 120V AC power source.
the high voltage must not, under any circumstances, exceed 32kV.
2 Each time a receiver requires servicing, the high voltage should be checked following the HIGH
VOLTAGE CHECK procedure in this manual. It is recommended the reading of the high voltage be
recorded as a part of service record. It is important to use an accurate and reliable high voltage meter.
3 This receiver is equipped with a Fail Safe (FS) circuit which prevents the receiver from producing an
excessively high voltage even if the B+ voltage increases abnormally. Each time the receiver is serviced,
the FS circuit must be checked to determine that the circuit is properly functioning, following the FS
CIRCUIT CHECK procedure in this manual.
4 The primary source of X-RAY RADIATION in this TV receiver is the picture tube. For continuous X-RAY
RADIATION protection, the replacement tube must be exactly the same type tube as specified in the parts
list.
5 Some parts in this receiver have special safety-related characteristics for X-RAY RADIATION protection.
For continuous safety, parts replacement should be undertaken only after referring to the PRODUCT
SAFETY NOTICE below.
SAFETY PRECAUTION
WARNING:
Service should not be attempted by anyone unfamiliar with the necessary precaution on this receiver. The
following are the necessary precautions to be observed before servicing this chassis.
1) Since the power supply circuit of this receiver is directly connected to the AC power line, an isolation
transformer should be used during any dynamic service to avoid possible shock hazard.
2) Always discharge the picture tube anode to the CRT conductive coating before handling the picture tube.
The picture tube is highly evacuated and if broken, glass fragments will be violently expelled. Use shatter
proof goggles and keep picture tube away from the unprotected body while handling.
3) When replacing a chassis in the cabinet, always be certain that all the protective devices are put back in
place, such as: non-metallic control knobs, insulating covers, shields, isolation resistor-capacitor network
etc.
4) When replacing parts or circuit boards, disconnect the power cord.
5) When replacing a high wattage resistor (oxiode metal film resistor) on the circuit board, keep the resistor
10mm (1/2in) away from circuit board.
6) Connection wires must be kept away from components with high voltage or high temperature.
7) If any fuse in this TV receiver is blown, replace it with the FUSE specified in the chassis parts list.
1
8) Before returning the set to your customer, always perform an AC leakage current check on the exposed
metallic parts of the cabinet, such as antennas, terminals, screwheads, metal overlays, control shafts etc. to
be sure the set is safe to operate without danger of electrical shock. Plug the AC line cord directly into a
120V AC outlet (do not use a line isolation transformer during this check). Use an AC voltmeter having
5000 ohms per volt or more sensitivity in the following manner:
Connect a 1500 ohm 10 watt resistor, paralleled by a 0.15 F, AC type capacitor, between a known good
earth ground (water pipe, conduit, etc.) and the exposed metallic parts, one at a time. Measure the AC
voltage across the combination of 1500 ohm resistor and 0. 15 F capacitor. Reverse the AC plug at the
AC outlet and repeat AC voltage measurements for each exposed metallic part. Voltage measured must not
exceed 0.3 volts RMS. This corresponds to o.2 milliamp. AC. Any value exceeding this limit constitutes a
potential shock hazard and must be corrected immediately.
AC VOLTMETER
0.15 FD
Place this probe on
each exposed
metallic part.
Good earth ground
such as a water
pipe, conduit, etc.
1500ohm
10watt
PRODUCT SAFETY NOTICE
Many electrical and mechanical parts in the chassis have special safety-related characteristics. These
characteristics are often passed unnoticed by a visual inspection and the X-RAY RADIATION protection
afforded by them cannot necessarily be obtained by using replacement components rated for higher wattage,
etc. Replacement parts which have these special safety characteristics are identified in this manual and its
supplement electrical components having such features are shaded on the schematic diagram and the parts list.
Before replacing any of these components, read the parts list in this manual carefully. The use of substitute
replacement parts which do not have the same characteristics as specified in the parts list may create shock,
fire, X-RAY RADIATION or other hazards.
B+ CHECK
1) Prepare the test equipment.
2) Use the DC voltameter at DC 200V position to test B+ test point, i.e. B+.
2
3) Connect the power plug to AC 120V/60Hz, turn on the power switch, wait for normal raster, Check B+ =
100V 0.2V.
Test point B+ B1-5V B2-9V B3-10V B4-32V TH-12V TH-20V TH-200V
DC(V) 100 5 9 12 32 12 20(22) 200
INSTALLATION AND SERVICE ADJUSTMENTS
GENERAL
In the majority of cases, a color television receiver will need only slight touch