Panasonic ct27g7df schematic

ORDER NO. MTNC020101A1 B5

Service Manual

Color Television

Simplified Manual

(NA7DM)

Panasonic

Models

CT-27G7DF JP363 CT-27G7DUF JP363 CT-27G7SDF JP363 CT-27G7SDUF JP363

This simplified service manual is issued to add listed models to the main service manual, order No. MTNC010306C1 (CT-27G6E); Models CT-27G7DF/DUF are similar to CT-27G6E. A full set of schematics, unique settings, and a com-

plete parts list are included in this simplified manual. Please file and use this simplified service manual together with main service manual, order No. MTNC010306C1.

“WARNING! ThisServiceManual is designedfor experienced repairtechniciansonly and isnot designedfor use bythe generalpublic. It does not contain warnings or cautions to advise non-technical individuals of potential dangers in attempting to service a product. Products poweredby electricity should be serviced or repaired only by experienced professionaltechnicians. 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

The service technician is requiredtoreadand follow the “Safety Precautions”and“Important Safety Notice” in this Manual.

Important Safety Notice

Special 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 that these 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 Precautions

General Guidelines

An Isolation Transformer should always be used during the servicing of a receiver whose chassis is not isolated from AC power line. Use a transformer of adequate power rating as this protects the technician from accidents resulting in personal injury from electrical shocks. It will also protect the receiver from being damaged by accidental shorting that may occur during servicing. When servicing, observe the original lead dress, especially in the high voltage circuit. Replace all damaged parts (also parts that show signs of overheating.) Always replace protective devices,suchas fishpaper, isolation resistors and capacitors, and shields after servicing the receiver. Use only manufacturer’s recommended rating for fuses, circuits breakers, etc. High potentials are present when this receiver is operating. Operation of the receiver without the rear cover introduces danger for electrical shock. Servicing should not be performed by anyone who is not thoroughly familiar with the necessary precautions when servicing high-voltage equipment.

Extreme care should be practiced when ha ndling the picture tube. Rough handling may cause it to implode

due to atmospheric pressure. (14.7 lbs per sq. in.). Do not nick or scratch the glass or subject it to any undue pressure. When handling, use safety goggles and heavy gloves for protection. Discharge the picture tube by shorting the anode to chassis ground (not to the cabinet or to other mounting hardware). When discharging connect cold ground (i.e. dag ground lead) to the anode with a well insulated wire or use a grounding probe. Avoid prolonged exposure at close range to unshielded areas of the picture tube to prevent exposure to x-ray radiation. The Test Picture Tube used for servicing the chassis at the bench should incorporate safety glass and magnetic shielding. The safety glass provide shielding for the tube viewing area against x-ray radiation as well as implosion. The magnetic shield limits the x-ray radiation around the bell of the picture tube in addition to the restricting magnetic effects. When using a picture tube test jig for service, ensure that the jig is capable of handling 50kV without causing x-ray radiation. Before returning a serviced Receiver to the owner, the service technician must thoroughly test the unit to ensure that is completely safe to operate. Do not use a

line isolation transformer when testing.

Leakage Current Cold Check

Unplug the AC cord and connect a jumper between the two plug prongs. Measure the resistance between the jumpered AC plug and expose metallic parts such as screwheads,

antenna terminals, control shafts, etc. If the exposed metallic part has a return path to the chassis, the reading should be between 240kΩ and 5.2MΩ. If the exposed metallic part does not have a return path to the chassis, the reading should be infinite.

Leakage Current Hot Check (Fig. 1)

Plug the AC cord directly into the AC outlet. Do not use an isolation transformer during the check. Connect a 1.5kΩ 10 watt resistor in p arallel with a

0.15µF capacitor between an exposed metallic part and ground. Use earth ground, for example a water pipe. Using a DVM with a 1000 ohms/volt sensitivity or higher, measure the AC potential across the resistor. Repeat the procedure and measure the voltage present with all other exposed metallic parts. Verify that any potential does not exceed 0.75 volt RMS. A leakage current tester (such a Simpson model 229, Sencore Model PR57 or equivalent) may be used in the above procedure, in which case any current measure must not exceed 0.5 milliamp. If any measurement is out of the specified limits, there is a possibility of a shock hazard and the receiver must be repaired and rechecked before it is returned to the customer.

Figure 1. Hot Check Circuit

X-ray Radiation

WARNING: The potential source of x-ray radiation in the

receiver is in the High Voltage section and the picture tube. Refer to “X-ray Protection Circuit Check & Adjustments” on page 5 to confirm HHS voltage.

High Voltage (CRT Anode)

Set the brightness, picture, sharpness and color controls to minimum (to obtain dark image). Measure the High V oltage. The high voltage should be

29.25kV ± 1.25kV. If the upper limit is out of tolerance, immediate service and correction is required.

Note: It is important to use an accurate, calibrated

high voltage meter.

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ImportantSafetyNotice .................. 2

SafetyPrecautions................. 2

ServiceNotes........................... 4

X-Ray Protection Circuit Check

&Adjustments................. 5

ReceiversFeatureTable.................. 6

LocationofReceiverControls............. 7

Chassisview........................... 8

PartsList .............................. 9

SchematicNotes....................... 14

A-Boardschematic..................... 16

A-BoardICvoltages .................... 21

A&C-Boardlayout..................... 22

C-Boardschematic..................... 24

A&C-transistorvoltages................ 27

A-Boardwaveforms..................... 27

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Service Notes

Note: Some components may be affixed with glue. Be careful not to break or damage 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.

Leadless Chip Component (surface mount)

Chip components must be replaced with identical chips due to critical foil track spacing. There are no holes in the board to mount standard transistors or diodes. Some chips capacitor or resistor board solder pads may have holes through the board, however the hole diameter limits standard resistor replacement to 1/8 watt. Standard capacitor may also be limited for the same reason. It is recommended that identical components be used. Chip resistor have a three digit numerical resistance code - 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 value indicated on the capacitor. The color of the component indicates the general range of the capacitance. Chip transistors are identified by a two letter code. The first letter indicates the type and the second letter, the grade of transistor. Chip diodes have a two letter identification code as per the code chart and are a dual diode pack with either common anode or common cathode. Check the parts list for correct diode number.

Component Removal

1. 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 stress fracture during removal.

Chip Component Installation

1. 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 clip and apply heat to the pad area with a 30 watt iron until solder flows. Do not apply heat for more than 3 seconds.

Chip Components

How to Replace Flat-IC

- Required Tools -

• Soldering iron • De-solder braids

• Needle nose pliers • Magnifier

• Wire cutters (sharp & small)

1. Cut the pins of a defective IC with wire cutters. Remove IC from board. If IC is glued to the board, heat the IC and release the IC. See Note above.

Flat IC

2. Using soldering iron and needle nose pliers remove the IC pins from the board.

Soldering Iron

3. Using de-soldering braid and soldering iron remove solder from affected are on board (pads).

De-soldering Braid

Soldering Iron

4. Position the new flat-ic in place (apply the pins of the flat-ic to the soldering pads where the pins need to be soldered). Determine the positions of the soldering pads and pins by correctly aligning the polarity symbol. Solder pin #1 first, align the IC.

Polarity symbol

Solder the pin opposite to pin #1. This will assist positioning the IC.

5. Solder all pins to the soldering pads using a fine tipped soldering iron.

2nd solder

1st solder

Solder

6. Check with a magnifier for solder bridge between the pins or for dry joint between pins and soldering pads. To remove a solder bridge, use a de-solder braid as shown in the figure below.

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Soldering Iron

IMPORTANT: To protect against possible damage to the solid state devices due to arcing or static discharge, make certain that all ground wires and CRT DAG wire are securely connected.

CAUTION: The power supply circuit is above earth ground and the chassis cannot be polarized. Use an isolation transformer when servicing the receiver to avoid damage to the test equipment or to the chassis. Connect the test equipment to the proper ground ( ) or

( ) when servicing, or incorrect voltages will be measured.

WARNING: This receiver has been designed to meet or exceed applicable safety and x-ray radiation protection as specified by government agencies and independent testing laboratories.

To maintain original product safety design standards relative to x-ray radiation and shock and fire hazard,

parts indicated with the symbol on the schematic must be replaced with identical parts. Order parts from

the manufacturer’s parts center using the parts numbers shown in this service manual, or provide the chassis number and the part reference number.

For optimum performance and reliability, all other parts should be replaced with components of identical specification.

X-ray Protection Circuit Check & Adjustments

This test must be performed as final check before the receiver is returned to the customer. If voltages are out of tolerance, immediate service and correction is required to insure safe operation and to prevent the possibility of premature component failure.

Equipment:

1. Isolation transformer.

2. High voltage meter.

3. Short jumper.

4. Jumper diode (same as D823, PN S3L60P154004). diode should be rated a minimum of 150V.

Procedure:

1. Connect the receiver to an isolation transformer. turn receiver ON.

2. Apply a monoscope pattern.

3. In service mode (see service mode section in this manual) select register C0B.

4. Measure TP5 (located near the tuner). Compare the measured value to the left column of the table below. Set C0B with value from the right column corresponding to the measured level at TP5. Example, if the measured level at TP5 is 1.03V, set C0B to 03.

TP5 MEASUREMENT SET C0B TO (HEX)

0 ~ 0.93V 00

0.93 ~ 0.97V 01

0.97 ~ 1.01V 02

1.01 ~ 1.05V 03

1.05 ~ 1.09V 04

1.09 ~ 1.13V 05

1.13 ~ 1.17V 06

1.17 ~ 1.21V 07

5. Exit service mode and shut the TV OFF.

6. Connect the short jumper between TPD16 and TPD17.

7. Connect the jumper diode between TPD14 and TPD15 (cathode connected to TPD14, anode connected to TPD15, see Fig. 3 for locations).

8. Apply 75VAC to the input of the isolation transformer.

9. Turn receiver ON.

10. Set PICTURE and BRIGHTNESS to minimum.

11. Slowly increase the voltage at the input of the isolation transformer and confirm HHS voltage measure 35.0KV when the receiver starts to go out of sync.

12. Turn receiver OFF and remove jumper & diode.

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Receiver Feature Table

FEA TURE / MODEL ALL MODELS

Chassis JP363 No. of channels 181 Menu language Eng/Span/Fr Closed Caption X V-Chip (USA/CANADA) X 75 Ω input X Remote model number EUR501450 Picture tube M68LGL061X Panablack tube X Comb filter 2Dig V/A norm V MTS/SAP/DBX X AI Sound X Built-in audio power 1.5W x 2 (10%) Number of speakers 2 A/V in (rear/front) 1(1/1) S-VHS input (rear/front) 1/0 Headphone jack X Dimensions mm

(WxDxH) in Weight (kg/lbs) 35 / 77.2 Power source (V/Hz) 120 / 60 Anode voltage 29.25kV ±1.25kV Video input jack Audio input jack 500mV RMS 47kΩ A-Board TNP2AH040 BH* C-Board TNP2AA106 AG*

665.2 x 545 x 594.8

26.2 x 21.5 x 23.4

75Ω, phono jack

p-p

Table 1. Receiver Features

Specifications are subject to change without notice or obligation. Dimensions and weights are approximate.

*Note:When ordering a replacement board assembly,

append an “S” next to the board number. Example: to order the A-Board for CT-27G7DF, the replacement board is

TNP2AH040BHS

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Location of Receiver Controls

Remote control

sensor

4 5

Figure 2. Location of controls

Quick reference control operation

Power button - Press to turn ON or OFF. Volume buttons - Press to adjust sound level, or to adjust audio menus, video menus,

and select operating features when menus are displayed Channel buttons - Press to select programmed channels. Press to highlight desired

features when menus are displayed. Also use to select cable converter box channels

after programming remote control infra-red codes (the TV/AUX/CABLE switch must be set in CABLE position).

Action button - Press to display main menu and access on screen feature and

adjustment menus.

TV/Video button - Press to select TV or video input.

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Chassis View

Figure 3. A-Board main

components and test points

(components within dotted

areas are located on

trace side)

HPJ output

Front A/V inputs

Back S-Video input

Back A/V inputs

Figure 4. Chassis view

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REPLACEMENT PARTS LIST

Models: CT-27G7DF, CT-27G7DUF, CT-27G7SDF & CT-27G7SDUF

Important Safety Notice: Components printed in BOLD TYPE have special characteristics important for safety. When replacing

any of these components use only manufacturer’s specified parts.

REF NO. PART NO. DESCRIPTION

CAPACITORS

C001 TCJ2VF1H103Z CAP,C .01UF-Z-50V

C002 TCJ2VB1H471K CAP,C 470PF-K-50V C003 ECA1HM4R7B CAP,E 4.7UF-50V C004 TCJ2VC1H150J CAP,C 15PF-J-50V C005 TCJ2VC1H150J CAP,C 15PF-J-50V C008 TCJ2VF1H104Z CAP,C .1UF-Z-50V C009 ECA1AM470B CAP,E 47UF-10V C010 TCJ2VF1H104Z CAP,C .1UF-Z-50V C011 ECA1AM101B CAP,E 100UF-10V C015 ECJ2VB1C224K CAP,C .22UF-K-16V C016 TCJ2VC1H101J CAP,C 100PF-J-50V C017 TCJ2VB1C104K CAP,C .1UF-K-16V C018 TCJ2VC1H151J CAP,C 150PF-J-50V C020 TCJ2VB1C104K CAP,C .1UF-K-16V C022 TCJ2VC1H101J CAP,C 100PF-J-50V C023 TCJ2VC1H151J CAP,C 150PF-J-50V C024 ECA1AM470B CAP,E 47UF-10V C025 TCJ2VB1C104K CAP,C .1UF-K-16V C026 TCJ2VB1C104K CAP,C .1UF-K-16V C027 TCJ2VF1H104Z CAP,C .1UF-Z-50V C028 TCJ2VB1C104K CAP,C .1UF-K-16V C029 ECQB1H333JF3 CAP,P .033UF-J-50V C031 ECA1HMR22B CAP,E .22UF-50V C032 ECA1AM470B CAP,E 47UF-10V C033 TCJ2VC1H390J CAP,C 39PF-J-50V C034 TCJ2VF1H103Z CAP,C .01UF-Z-50V C035 ECA1HM010B CAP,E 1UF-50V C036 TCJ2VF1H103Z CAP,C .01UF-Z-50V C037 ECA1HM0R1B CAP,E 0.1UF/50V C038 ECA1AM470B CAP,E 47UF-10V C040 ECA1AM470B CAP,E 47UF-10V C041 ECA1HM2R2B CAP,E 2.2UF-50V C042 TCJ2VF1H104Z CAP,C .1UF-Z-50V C043 ECA1AM470B CAP,E 47UF-10V C044 TCJ2VC1H471J CAP,C 470PF-J-50V C045 ECA1HM0R1B CAP,E 0.1UF/50V C046 TCJ2VB1C104K CAP,C .1UF-K-16V C047 TCJ2VC1H220J CAP,C 22PF-J-50V C048 TCJ2VC1H220J CAP,C 22PF-J-50V C050 ECA1AM101B CAP,E 100UF-10V C051 TCJ2VF1H104Z CAP,C .1UF-Z-50V C055 TCJ2VC1H560J CAP,C 56PF-J-50V C103 ECA0JM331B CAP,E 330UF-6.3V C104 TCJ2VF1H103Z CAP,C .01UF-Z-50V C105 ECA0JM101B CAP,E 100UF-6.3V C350 ECA1CM101B CAP,E 100UF/16V C351 TCJ2VB1H391K CAP,C 390PF-K-50V C352 TCJ2VB1H391K CAP,C 390PF-K-50V C353 TCJ2VB1H471K CAP,C 470PF-K-50V C354 ECKW3D102KBN CAP,C .001UF-K-2KVDC

REF NO. PART NO. DESCRIPTION

C357 EEANA1E1R0B CAP,E 1.0UF-25V C361 TCJ2VC1H151J CAP,C 150PF-J-50V C362 TCJ2VC1H151J CAP,C 150PF-J-50V C363 TCJ2VC1H151J CAP,C 150PF-J-50V C451 ECA1CHG470B CAP,E 47UF-16V C452 ECSF1EE105VB CAP,E 1.0UF-25V C453 ECEA1HFS010B CAP,E 1UF-50V C454 ECA1EM102E CAP,E 1000UF-25V C455 ECA1VHG101B CAP,E 100UF-35V C456 ECQB1H103JF3 CAP,P .01UF-J-50V C459 ECA1VHG471B CAP,E 470UF-35V C462 ECA1HM4R7B CAP,E 4.7UF-50V C502 TCJ2VC1H471J CAP,C 470PF-J-50V C503 TCJ2VB1C104K CAP,C .1UF-K-16V C504 TCJ2VB1C104K CAP,C .1UF-K-16V C510 ECCR2H100D5 C AP,C 10PF-D-500V C511 ECKR2H821KB5 CAP,C 820PF-K-500V C512 ECKR2H101KB5 CAP,C 100UF-K-500V

C531 ECA1EM220B CAP,E 22UF-25V C551 ECA1VM331B CAP,E 330UF-35V

C554 ECKR2H561KB5 CAP,C 560PF-K-500V

C555 ECA2EM220E CAP,E 22UF-250V C556 ECA1CM471B CAP,E 470UF-16V

C557 ECKR2H102KB5 CAP,C 1000PF-K-500V

C560 ECEA1HN010UB CAP,E 1UF/50V

C561 ECKR2H561KB5 CAP,C 560PF-K-500V

C563 ECWH12H822JS CAP,P .0082UF-J-1.2KV C564 ECWH12H562JS CAP,P .0056UF-J-1.2KV C565 ECKW3D181JBP CAP,C 180PF-J-2KV C566 ECKW3D181JBP CAP,C 180PF-J-2KV C568 ECWF2274JBB CAP,M .27UF-J-200V C569 ECWF2474JBB CAP,M .24UF-J-200V

C570 ECA1CM222E CAP,E 2200UF-16V C571 ECA1EM220B CAP,E 22UF-25V C572 ECA1CM100B CAP,E 10UF-16V C573 ECA1CM101B CAP,E 100UF/16V C575 ECA0JM222B CAP,E 2200UF-6.3V C577 ECA1CM101B CAP,E 100UF/16V C578 ECA0JM332B CAP,E 3300PF-6.3V C579 TCJ2VF1H103Z CAP,C .01UF-Z-50V C580 ECKR2H152KB5 CAP,C .0015UF-K-500V C605 TCJ2VF1H103Z CAP,C .01UF-Z-50V C606 ECA0JM221B CAP,E 220UF-6.3V

C801 ECKWAE472ZED CAP,C 4700PF-Z-500V C802 ECKWAE472ZED CAP,C 4700PF-Z-500V C803 ECKWAE472ZED CAP,C 4700PF-Z-500V C805 EC0S2DA331BB CAP,E 330UF/200V

C806 ECQM4103KZW C AP,P .01UF-K-400V C807 ECKR3A821KBP CAP,C 820PF-K-1KV C808 ECA1VM101B CAP,E 100UF-35V C809 ECKR1H101KB5 CAP,C 100PF-K-50V

PARTS LIST

022-02

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Parts List

+ 19 hidden pages