Panasonic The service technician is required to read and follow the “ safety precautions” and “important safety notice” in this main manual. Service Manual Color Television (NA7DM) Simplified Manual Copyright 2002 by Matsushita Electric Corporation of America. All rights reserved. Unauthorized copying and distribution is a violation of law. “WARNING! This Service Manu al is des ign ed for e xpe rienced repa ir technicians onl y and is not des ign ed fo r use by the gen era l pub lic. It does not contain warnings or cautions to advise non-technical individuals of potential dangers in attempting to service a product. Products powered by electricity should be serviced or repaired only by experienced professional technicians. Any attempt to service or repair the product or products dealt with in this Service Manual by anyone else could result in serious injury or death.” Chassis CT-20G7DF-1 DP391 CT-20D12DF-1 EP391 CT-2017F-1 DP391 Models ORDER NO. MTNC021096A1 B1 This supplement service manual is issued to ADD the models of the NA7DM family listed above to the simplified service manual order No. MTNC020515A1 (CT-20D12F). Included in this supplement service manual are unique characteristics and a complete parts list. Please file and use this simplified service manual together with the simplified service manual order No. MTNC020515A1 (CT-20D12F) and the main service manual order No. MTNC010305C1 (CT-32D11E). S i m p l i f i e d Since “-1” and non dash models have different PCB layouts and parts; When servicing any of these models please confirm the model number before starting service so the correct manual is used. Importan t notice:
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
The service technician is required to read and follow the “ safety precautions” and “important safety notice” in this main manual.
Service ManualColor Television
(NA7DM)Simplified Manual
Copyright 2002 by Matsushita Electric Corporation oAmerica. All rights reserved. Unauthorized copyinand distribution is a violation of law.
“WARNING! This Service Manual is designed for experienced repair technicians only and is not designed for use by the general publicIt does not contain warnings or cautions to advise non-technical individuals of potential dangers in attempting to service a product.Products powered by electricity should be serviced or repaired only by experienced professional technicians. Any attempt toservice or repair the product or products dealt with in this Service Manual by anyone else could result in serious injury or death.”
This supplement service manual is issued to ADD the models of the NA7DM family listed above to the simplifiedservice manual order No. MTNC020515A1 (CT-20D12F). Included in this supplement service manual are uniquecharacteristics and a complete parts list. Please file and use this simplified service manual together with the simplifiedservice manual order No. MTNC020515A1 (CT-20D12F) and the main service manual order No. MTNC010305C1(CT-32D11E).
S i m p l i f i e d
Since “-1” and non dash models have different PCB layouts and parts;When servicing any of these models please confirm the model numberbefore starting service so the correct manual is used.
Important safety noticeSpecial components are used in this television set which are important for safety. These parts are identified on the
schematic diagram by the symbol and printed in BOLD TYPE on the replacement part list. It is essential thatthese critical parts are replaced with the manufacturer’s specified replacement part to prevent x-ray radiation,shock, fire or other hazards. Do not modify the original design without the manufacturer’s permission.
Safety precautionsGeneral guidelinesAn Isolation Transformer should always be usedduring the servicing of a receiver whose chassis is not
isolated from AC power line. Use a transformer ofadequate power rating as this protects the technicianfrom accidents resulting in personal injury fromelectrical shocks. It will also protect the receiver frombeing damaged by accidental shorting that may occurduring servicing.When servicing, observe the original lead dress,especially in the high voltage circuit. Replace alldamaged parts (also parts that show signs ofoverheating.)Always replace protective devices, such asfishpaper, isolation resistors and capacitors, andshields after servicing the receiver. Use onlymanufacturer’s recommended rating for fuses, circuits
breakers, etc.High potentials are present when this receiver isoperating. Operation of the receiver without the rearcover introduces danger for electrical shock. Servicingshould not be performed by anyone who is notthoroughly familiar with the necessary precautionswhen servicing high-voltage equipment.Extreme care should be practiced when handling thepicture tube. Rough handling may cause it to implodedue to atmospheric pressure. (14.7 lbs per sq. in.). Donot nick or scratch the glass or subject it to any unduepressure. When handling, use safety goggles andheavy gloves for protection. Discharge the picturetube by shorting the anode to chassis ground (not to
the cabinet or to other mounting hardware). Whendischarging connect cold ground (i.e. dag ground lead)to the anode with a well insulated wire or use agrounding probe.Avoid prolonged exposure at close range to unshieldedareas of the picture tube to prevent exposure tox-ray radiation.The test picture tube used for servicing the chassis atthe bench should incorporate safety glass andmagnetic shielding. The safety glass provide shieldingfor the tube viewing area against x-ray radiation as wellas implosion. The magnetic shield limits the x-rayradiation around the bell of the picture tube in additionto the restricting magnetic effects. When using a
picture tube test jig for service, ensure that the jig iscapable of handling 35kV without causingx-ray radiation.Before returning a serviced receiver to the owner,the service technician must thoroughly test the unit toensure that is completely safe to operate. Do not use aline isolation transformer when testing.
Leakage current cold checkUnplug the AC cord and connect a jumper between thetwo plug prongs.Measure the resistance between the jumpered AC plugand expose metallic parts such as screwheads,antenna terminals, control shafts, etc.
If the exposed metallic part has a return path to thechassis, the reading should be between 240kΩ and
5.2MΩ. If the exposed metallic part does not have areturn path to the chassis, the reading should beinfinite.
Leakage current hot check (Fig. 1)
Plug the AC cord directly into the AC outlet. Do not usean isolation transformer during the check.Connect a 1.5kΩ 10 watt resistor in parallel with a0.15µF capacitor between an exposed metallic partand ground. Use earth ground, for example awater pipe.Using a DVM with a 1000 ohms/volt sensitivity orhigher, measure the AC potential across the resistor.Repeat the procedure and measure the voltagepresent with all other exposed metallic parts.Verify that any potential does not exceed 0.75 voltRMS. A leakage current tester (such a Simpson model229, Sencore model PR57 or equivalent) may be usedin the above procedure, in which case any currentmeasure must not exceed 0.5 milliamp. If anymeasurement is out of the specified limits, there is apossibility of a shock hazard and the receiver must berepaired and rechecked before it is returned to thecustomer.
X-ray radiationWARNING: The potential source of x-ray radiation in theTV set are the high voltage section and the picture tube.Refer to x-ray protecton circuit check in servicenotes in this manual to confirm HHS voltage.
High voltage (CRT anode)Confirm anode voltage is within limits:Set the BRIGHTNESS, PICTURE, SHARPNESS andCOLOR to minimum (to obtain a dark image). Measurehigh voltage. It should be:26.60 ± 1.25kV.If the upper limit is out of tolerance, immediate serviceand correction is required.
Note: It is important to use an accurate, calibrated high voltage meter.
Leadless chip component(surface mount)Chip components must be replaced with identical chipsdue to critical foil track spacing. There are no holes inthe board to mount standard transistors or diodes.Some chips capacitor or resistor board solder padsmay have holes through the board, however the holediameter limits standard resistor replacement to 1/8watt. Standard capacitor may also be limited for thesame reason. It is recommended that identicalcomponents be used.Chip resistor have a three digit numerical resistancecode - 1st and 2nd significant digits and a multiplier.Example: 162 = 1600 or 1.6kΩ resistor, 0 = 0Ω (jumper).Chip capacitors generally do not have the valueindicated on the capacitor. The color of the componentindicates the general range of the capacitance.Chip transistors are identified by a two letter code. Thefirst letter indicates the type and the second letter, thegrade of transistor.Chip diodes have a two letter identification code as perthe code chart and are a dual diode pack with eithercommon anode or common cathode. Check the partslist for correct diode number.
Component removal1. Use solder wick to remove solder from component
end caps or terminal.2. Without pulling up, carefully twist the component
with tweezers to break the adhesive.3. Do not reuse removed leadless or chip
components since they are subject to stressfracture during removal.
Chip component Installation1. Put a small amount of solder on the board
soldering pads.2. Hold the chip component against the soldering
pads with tweezers or with a miniature alligator clipand apply heat to the pad area with a 30 watt ironuntil solder flows. Do not apply heat for more than3 seconds.
How to replace Flat-IC- Required tools -
1. Cut the pins of the defective IC with the wire cutterspliers, and remove it completely away from theboard. If the IC is glued to the board, apply hot airto complete the removal. CAUTION- Do not pull ortwist the pliers, may damage the soldering pads inthe board.
2. Using the soldering Iron and the long nose pliers,remove the IC pins that still attached to the board.
3. Using the de-solder braid and the soldering iron,remove the solder from the board soldering pads.
4. Position the new Flat-IC in place (apply the pins of
the Flat-IC to the soldering pads where the pinsneed to be soldered). Properly determine thepositions of the soldering pads and pins bycorrectly aligning the polarity symbol. Start aligningand soldering pin no.1, then align and solder thepin in the apposite corner of the IC, this will help toalign the rest of the pins.
5. Solder all pins to the soldering pads using a finetipped soldering iron.
6. Check with a magnifier for solder bridge betweenthe pins or for dry joint between pins and solderingpads. To remove a solder bridge, use a de-solderbraid as shown in the figure below.
Note: These components are affixed with glue. Be careful not to break or damage any foil under the component or at the pins of the ICs when removing. Usually applying heat to the component for a short time
while twisting with tweezers will break the component loose.
Service notes (continued)IMPORTANT: To protect against possible damage tothe solid state devices due to arcing or static discharge,make certain that all ground wires and CTR DAG wireare securely connected.
CAUTION: The power supply circuit is above earthground and the chassis cannot be polarized. Use an
isolation transformer when servicing the receiver toavoid damage to the test equipment or to the chassis.Connect the test equipment to the proper ground ( ) or( ) when servicing, or incorrect voltages will bemeasured.
WARNING: This receiver has been designed to meetor exceed applicable safety and x-ray radiationprotection as specified by government agencies andindependent testing laboratories.
To maintain original product safety design standardsrelative to x-ray radiation and shock and fire hazard,
parts indicated with the symbol on the schematicmust be replaced with identical parts. Order parts fromthe manufacturer’s parts center using the partsnumbers shown in this service manual, or provide thechassis number and the part reference number.
For optimum performance and reliability, all other partsshould be replaced with components ofidentical specification.
X-ray protection circuit check
This test must be performed as final check before thereceiver is returned to the customer. If voltage is out of
tolerance, immediate service and correction is requiredto insure safe operation and to prevent the possibility ofpremature component failure.
Equipment needed to check the protection circuit:
1. Isolator transformer.2. High voltage meter.3. Short jumper.4. Diode connection jumper.
Use similar diode than D823, refer to parts list for part No., (diode should support at least 150V.)
Procedure:1. Connect receiver to isolator transformer.2. Apply a monoscope pattern.3. In service mode. (Refer to service mode section
select register C0B.4. Measure TP5 (TPs port close to tuner). Compare
the measure of TP5 and set the data for C0Baccording the following table
5. Exit service mode and turn receiver OFF.6. Connect a jumper from TPD16 to TPD17.7. Connect the diode jumper , cathode to TPD14
(cold GND), anode to TPD15 (hot GND).Note: Refer to Fig. 2 for test point location.
8. Apply 75V AC to the AC input of the Insulato
transformer.Turn receiver ON.9. Set PICTURE and BRIGTHNESS to minimum.10. Increase the AC voltage at the input of Insulator
transformer and confirm the HHS voltage is32.0kV, at the point set starts to loose sync,
11. Reset picture controls to original levels.12. Turn the set OFF, and remove all jumpers and
http://slidepdf.com/reader/full/panasonic-ct-20g7df-chasis-dp391 8/30- 8 -Parts List
REPLACEMENT PARTS LISTModels: CT-20G7DF-1, CT-20D12DF-1, CT-2017F-1
Important Safety Notice: Components printed in BOLD TYPE have special characteristics important for safety. When replacingany of these components use only manufacturer’s specified parts.
REPLACEMENT PARTS LISTModels: CT-20G7DF-1, CT-20D12DF-1, CT-2017F-1
Important Safety Notice: Components printed in BOLD TYPE have special characteristics important for safety. When replacingany of these components use only manufacturer’s specified parts.
http://slidepdf.com/reader/full/panasonic-ct-20g7df-chasis-dp391 10/30- 10 -Parts List
REPLACEMENT PARTS LISTModels: CT-20G7DF-1, CT-20D12DF-1, CT-2017F-1
Important Safety Notice: Components printed in BOLD TYPE have special characteristics important for safety. When replacingany of these components use only manufacturer’s specified parts.
REPLACEMENT PARTS LISTModels: CT-20G7DF-1, CT-20D12DF-1, CT-2017F-1
Important Safety Notice: Components printed in BOLD TYPE have special characteristics important for safety. When replacingany of these components use only manufacturer’s specified parts.
http://slidepdf.com/reader/full/panasonic-ct-20g7df-chasis-dp391 12/30- 12 -Parts List
REPLACEMENT PARTS LISTModels: CT-20G7DF-1, CT-20D12DF-1, CT-2017F-1
Important Safety Notice: Components printed in BOLD TYPE have special characteristics important for safety. When replacingany of these components use only manufacturer’s specified parts.
REPLACEMENT PARTS LISTModels: CT-20G7DF-1, CT-20D12DF-1, CT-2017F-1
Important Safety Notice: Components printed in BOLD TYPE have special characteristics important for safety. When replacingany of these components use only manufacturer’s specified parts.
(Measurement can be taken at the bestaccessible location in common to theindicated point.)
2. Taken with an NTSC signal generatorconnected to the antenna terminal.
(NTSC color bar pattern of 8 bars of EIAcolors, 100 IRE white and 7.5 IRE black.)
3. Customer Controls (Picture/Audio Menu) areset to Normalize. Volume is set to “MIN”.
4. All video and color waveforms are takenwith a wideband scope and a probewith low capacitance (10 to 1). Shapeand peak alti tudes may varydepending on the type of Oscilloscopeused and its settings.
5. Ground symbol shown on waveformnumber indicates (Hot) ground leadconnection of the Oscilloscope.
CAUTION: Incorrect ground connection of
the test equipment will result in erroneous
readings.
3
VOLTAGE MEASUREMENTS1. Voltage measurement:
- AC input to the Receiver is 120V.NTSC (HD, 1125i & 525P whenapplicable) signal generator isconnected to the antenna of theReceiver. (Color bar pattern of 100IRE white and 7.5 IRE black.)
- All Picture and Audio adjustments areset to Normalize.TV ANT/CABLE - (Set-Up Menu) in
- Voltage readings are nominal andmay vary ±10% on active devices.Some voltage reading will varywith signal strength and picturecontent.
- Supply voltages are nominal.
2. Ground symbol indicates ground leadconnection of meter.Incorrect ground connection will resultin erroneous readings.
CAUTION: Incorrect ground connection of the test equipment will result in
erroneous readings.
IMPORTANT SAFETY NOTICETHIS SCHEMATIC DIAGRAM INCORPORATES SPECIALFEATURES THAT ARE IMPORTANT FOR PROTECTION FROMX-RADIATION, FIRE AND ELECTRICAL SHOCK HAZARDS.WHEN SERVICING IT IS ESSENTIAL THAT ONLYMANUFACTURERS SPECIFIED PARTS BE USED FOR THECRITICAL COMPONENTS DESIGNATED WITH A IN THESCHEMATIC.