Panasonic PV-20DF25 Schematic

ORDER NO. MKE0503601C1

TV/DVD Combination

PV-20DF25 PV-27DF25 PV-27DF5 PV-20DF25-K PV-27DF25-K

B6, B22

PV-20DF25 / PV-27DF25 / PV-27DF5 / PV-20DF25-K / PV-27DF25-K

CONTENTS

Page Page

1 SAFETY PRECAUTIONS 3

1.1. GENERAL GUIDELINES

1.2. LEAKAGE CURRENT COLD CHECK

1.3. LEAKAGE CURRENT HOT CHECK

2 X-RADIATION

2.1. HORIZONTAL OSCILLATOR DISABLE CIRCUIT TEST

2.2. REPAIR PROCEDURES OF HORIZONTAL OSCILLATOR DISABLE CIRCUIT

2.3. CIRCUIT EXPLANATION

2.4. LASER PRODUCT

2.5. PRECAUTION OF LASER DIODE

3 PREVENTION OF ELECTROSTATIC DISCHARGE (ESD) TO

ELECTROSTATICALLY SENSITIVE (ES) DEVICES 4 ABOUT LEAD FREE SOLDER (PbF) 5 SERVICE NOTES (PLEASE READ)

5.1. SERVICE NOTES

6 DISASSEMBLY/ASSEMBLY PROCEDURES

6.1. CABINET SECTION

7 ADJUSTMENT PROCEDURES

7.1. SERVICE FIXTURES AND TOOLS

7.2. ELECTRICAL ADJUSTMENT

7.3. TEST POINTS AND CONTROL LOCATION

8 SCHEMATIC DIAGRAMS

8.1. SCHEMATIC DIAGRAM AND CIRCUIT BOARD LAYOUT NOTES

21 22 29

3 3 3

4 4 5 5

6 7 8

8.2. MAIN SCHEMATIC DIAGRAMS

8.3. DEFLECTION SCHEMATIC DIAGRAMS

8.4. OPERATION / CRT (Models : PV-20DF25 / PV-20DF25K) SCHEMATIC DIAGRAMS

8.5. CRT SCHEMATIC DIAGRAM (Models : PV-27DF25 / PV27DF25-K / PV-27DF5)

8.6. DVD MAIN / DVD SUB SCHEMATIC DIAGRAMS

8.7. INTERCONNECTION SCHEMATIC DIAGRAM

8.8. VOLTAGE CHART

9 CIRCUIT BOARD LAYOUT

9.1. MAIN C.B.A.

9.2. OPERATION C.B.A.

9.3. DEFLECTION / CRT C.B.A.

9.4. DVD MAIN / DVD SUB C.B.A.

10 B LOCK DIAGRAMS 11 EXPLODED VIEWS

11.1. DVD SECTION

11.2. CHASSIS FRAME SECTION (1)

11.3. CHASSIS FRAME SECTION (2)

11.4. CHASSIS FRAME SECTION (3)

11.5. PACKING PARTS AND ACCESSORIES SECTION

12 REPLACEMENT PARTS LISTS

12.1. REPLACEMENT NOTES

12.2. MECHANICAL REPLACEMENT PARTS LIST

12.3. ELECTRICAL REPLACEMENT PARTS LIST

32 39

41 42 47 48

51 52 53 54

55 67

67 68 69 70 71

72 73 74

1 SAFETY PRECAUTIONS

1.1. GENERAL GUIDELINES

1. IMPORTANT SAFETY NOTICE There are special components used in this equipment

which are important for safety. These parts are marked by

in the Schematic Diagrams, Circuit Board Layout, Exploded Views and Replacement Parts List. It is essential that these critical parts should be replaced with manufacturer’s specified parts to prevent X-RADIATION, shock, fire, or other hazards. Do not modify the original design without permission of manufacturer.

2. An Isolation Transformer should always be used during the servicing of Combination TV/DVD whose chassis is not isolated from the 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 Combination TV/DVD from being damaged by accidental shorting that may occur during servicing.

3. When servicing, observe the original lead dress, especially the lead dress in the high voltage circuits. If a short circuit is found, replace all parts which have been overheated or damaged by the short circuit.

4. After servicing, see to it that all the protective devices such as insulation barriers, insulation papers, shield, and isolation R-C combinations are properly installed.

5. Before turning the receiver on, measure the resistance between B+ line and chassis ground. Connect (-) side of an ohmmeter to the B+ lines, and (+) side to chassis ground. Each line should have more resistance than specified, as follows :

B+ Line Minimum Resistance 130 V 110 Ω (Cold chassis ground) 28 V 180 Ω (Cold chassis ground) 220 V 1 kΩ (Cold chassis ground)

6. When the TV set is not used for a long period of time, unplug the power cord from the AC outlet.

7. Potentials, as high as 33.0 kV is present when this TV set is in operation. Operation of the TV set without the rear cover involves the danger of a shock hazard from the TV set power supply. Servicing should not be attempted by anyone who is not thoroughly familiar with the precautions necessary when working on high voltage equipment. Always discharge the anode of the picture tube to the CRT ground of receiver before handling the tube.

8. After servicing make the following leakage current checks to prevent the customer from being exposed to shock hazards.

PV-20DF25 / PV-27DF25 / PV-27DF5 / PV-20DF25-K / PV-27DF25-K

1.2. LEAKAGE CURRENT COLD CHECK

1. Unplug the AC cord and connect a jumper between the two

prongs on the plug.

2. For physically operated power switches, turn power on.

Otherwise skip step 2.

3. Measure the resistance value, with an ohmmeter, between

the jumpered AC plug and each exposed metallic cabinet part on the receiver, such as screwheads, connectors, etc. When the exposed metallic part has a return path to the chassis, the reading should be between 1 MΩ and 12 MΩ. When the exposed metal does not have a return path to the chassis, the reading must be infinity.

1.3. LEAKAGE CURRENT HOT CHECK

1. Plug the AC cord directly into the AC outlet.

Do not use a isolation transformer for this check.

2. Connect a 1.5 kΩ, 10 W resistor, in parallel with a 0.15 µF

capacitor, between each exposed metallic part on the set and a good earth ground, as shown in Figure 1.

3. Use an AC voltmeter, with 1 kΩ/V or more sensitivity, to

measure the potential across the resistor.

4. Check each exposed metallic part, and measure the

voltage at each point.

5. Reverse the AC plug in the AC outlet and repeat each of the

above measurements.

6. The potential at any point should not exceed 0.75 V RMS.

A leakage current tester (Simpson Model 229 equivalent) may be used to make the hot checks. Leakage current must not exceed 1/2 mA. In case a measurement is outside of the limits specified, there is a possibility of shock hazard, and the receiver should be repaired and rechecked before it is returned to the custom er.

Figure 1

PV-20DF25 / PV-27DF25 / PV-27DF5 / PV-20DF25-K / PV-27DF25-K

2 X-RADIATION

WARNING :

1. The potential source of X-Radiation in TV sets is the High Voltage section and the picture tube.

2. When using a picture tube test fixture for service, ensure that the fixture is capable of handling 33.0 kV without causing X-Radiation.

NOTE:

It is important to use an accurate periodically calibrated high voltage meter.

1. Reduce the brightness to minimum.

2. Set the SERVICE switch to SERVICE.

3. Measure the High Voltage. The meter reading should indicate 28.0 kV±1.5 kV (For model with 20 inch CRT), 31.0 kV±2.0 kV (For model with 27 inch CRT).

If the meter indication is out of tolerance, immediate service and correction is required to prevent the possibility of premature component failure.

4. To prevent an X-Radiation possibly, it is essential to use the specified picture tube.

2.1. HORIZONTAL OSCILLATOR

DISABLE CIRCUIT TEST

SERVICE WARNING :

The test must be made as a final check before set is returned to the customer.

2.2. REPAIR PROCEDURES OF HORIZONTAL OSCILLATOR DISABLE CIRCUIT

1. Connect a DC voltmeter between capacitor C513 (+) on the

Main circuit board and chassis ground.

2. If approximately +21.5 V (For model with 20 inch CRT),

+20.0 V (For model with 27 inch CRT) is not present at that point when 120 V AC is applied, find the cause. Check R508, R503, R5504, D5505, D503, C513 and C5507.

3. Carefully check above specified parts and related circuits

and parts. When the circuit is repaired, try the horizontal oscillator disable circuit test again.

2.3. CIRCUIT EXPLANATION

2.3.1. HORIZONTAL OSCILLATOR

DISABLE CIRCUIT

The positive DC voltage, supplied from the D503 cathode for monitoring high voltage, is applied to the IC5301 Pin 11 through R508, R503 and R5504. Under normal conditions, the voltage at IC5301 Pin 11 is less than approx. 6 V. If the high voltage at Flyback Transformer Pin 5 exceeds the specified voltage, the positive DC voltage which is supplied from the D503 cathode also increases. The increased voltage is applied to IC5301 Pin 11 through R508, R503 and R5504. Due to the increased voltage at IC5301 Pin 11, the horizontal oscillator frequency increases, the picture goes out of horizontal sync, the beam current decreases and the picture become dark in order to keep X-radiation under specification.

CONFIRMATION OF X-RAY MOVEMENT

1. Turn off TV set.

2. Connect the circuit below between TP554 and TP553 on the Deflection C.B.A.

Figure 2

3. Turn on SW1 and then turn on the set. Confirm that the picture is on the screen properly.

4. Confirm that the picture goes out of horizontal sync while getting down by varying VR.

5. If this does not occur, it means that X-ray protect circuit is not operating. Further confirmation and repair is required.

Figure 3

2.4. LASER PRODUCT

CLASS I LASER PRODUCT

· This equipment is certified to comply with DHHS Rules 21 CFR Chapter 1, Subchapter J in effect as of date of manufacture. (Only for U.S.A.)

This equipment is classified as a Class I (Class 1) level LASER Product and there is no hazardous LASER radiation with the safety protection.

Caution:

Use of controls or adjustments or performance of procedures other than those specified herein may result in hazardous radiation exposure.

Never touch the internal parts in order to avoid EXPOSURE TO VISIBLE LASER RADIATION.

Unplug the AC power cord to the equipment when opening the top cover.

PV-20DF25 / PV-27DF25 / PV-27DF5 / PV-20DF25-K / PV-27DF25-K

When the power switch is On, do not place your eyes close to the front panel opening door or the other openings to look into the interior unit.

LASER Specification

Class I level A LASER Product (Class 1 level A LASER Product)

Wave Length: 640 - 677 nm (at DVD)

770 - 810 nm (at CD)

Laser Power: No hazardous radiation is emitted with

the safety protection.

2.5. PRECAUTION OF LASER

DIODE

CAUTION:

This unit utilizes a class III a laser. Visible laser radiation is emitted from the optical pickup lens when the unit is turned on:

1. Do not look directly into the pickup lens.

2. Do not use optical instruments to look at the pickup lens.

3. Do not adjust the preset variable resistor on the optical pickup.

4. Do not disassemble the optical pickup unit.

5. If the optical pickup is replaced, use the manufactures specified replacement pickup only.

6. Use of control or adjustment or performance of procedures other than those specified herein may result in hazardous radiation exposure.

PV-20DF25 / PV-27DF25 / PV-27DF5 / PV-20DF25-K / PV-27DF25-K

3 PREVENTION OF ELECTROSTATIC DISCHARGE (ESD)

TO ELECTROSTATICALLY SENSITIVE (ES) DEVICES

Some semiconductor (solid state) devices can be damaged easily by static electricity. Such components commonly are called Electrostatically Sensitive (ES) Devices. Examples of typical ES devices are integrated circuits and some field-effect transistors are semiconductor "chip" components. The following techniques should be used to help reduce the incidence of component damage caused by electrostatic discharge (ESD).

1. Immediately before handling any semiconductor component or semiconductor-equipped assembly, drain off any ESD on your body touching a known earth ground. Alternatively, obtain and wear a commercially available discharging ESD wrist strap, which should be removed for potential shock reasons prior to applying power to the unit under test.

2. After removing an electrical assembly equipped with ES devices, place the assembly on a conductive surface such as aluminum foil, to prevent electrostatic charge buildup or exposure of the assembly.

3. Use only a grounded-tip soldering iron to solder or unsolder ES devices.

4. Use only an anti-static solder removal device. Some solder removal devices not classified as "anti-static (ESD protected)" can generate electrical charge sufficient to damage ES devices.

5. Do not use freon-propelled chemicals. These can generate electrical charges sufficient to damage ES devices.

6. Do not remove a replacement ES device from its protective package until immediately before you are ready to install it. (Most replacement ES devices are packaged with leads electrically shorted together by conductive foam, aluminum foil or comparable conductive material).

7. Immediately before removing the protective material from the leads of a replacement ES device, touch the protective material to the chassis or circuit assembly into which the device will be installed.

CAUTION:

Be sure no power is applied to the chassis or circuit, and observe all other safety precautions.

8. Minimize bodily motions when handling unpackaged replacement ES devices. (Otherwise harmless motion such as the brushing together of your clothes fabric or the lifting of your foot from a carpeted floor can generate static electricity (ESD) sufficient to damage an ES device).

"NOTEtoCATVsysteminstaller:

This reminder is provided to call the CATV system installer’s attention to Article 820-40 of the NEC that provides guidelines for proper grounding and, in particular, specifies that the cable ground shall be connected to the grounding system of the building, as close to the point of cable entry as practical."

4 ABOUT LEAD FREE SOLDER (PbF)

PV-20DF25 / PV-27DF25 / PV-27DF5 / PV-20DF25-K / PV-27DF25-K

5 SERVICE NOTES (PLEASE READ)

5.1. SERVICE NOTES

5.1.1. SIMPLIFIED FAULT FINDING DATA

Simplified Self-Diagnostic System facilitates finding the cause of the fault. The Communication for I displayed on the TV screen.

The Simplified Fault finding data is stored in the Memory IC (IC6004). This data is cleared after it is displayed, and then the POWER button is pressed back on.

1. With power turned off, press PLAY and SKIP+ buttons on the unit together for over 3 seconds.

Fig. 1-1

2. TV power comes on and the unit goes into service mode. The Communication for I

C bus code will be displayed.

C bus code will be

Fig. 1-4

Fig. 1-2

Fig. 1-3

Note:

Press any operation button except for POWER or PLAY buttons on either the unit, or DVD key on the remote to detect that a key has been pressed. The 3rd digit changes to "1" only when key is detected.

5.1.2. USAGE SCREEN MODE

This function is displayed on the TV monitor:

· the total AC plugged in AC socket (in days)

· the total elapsed "DVD play" time (in hours).

1. With power turned, press STOP button on the unit and 7 key on the remote together.

The USAGE SCREEN will be displayed on the TV Monitor.

Fig. 2

Note:

1. After replacing the DVD Unit, press ADD/DLT button on remote in this mode. Only Total elapsed time "DVD Play" time (in hours) will be cleared to 0.

2. To release from Usage Screen Mode, press any operation button or insert a cassette tape in this mode. The unit will return to normal operation mode.

PV-20DF25 / PV-27DF25 / PV-27DF5 / PV-20DF25-K / PV-27DF25-K

5.1.4. METHOD FOR EJECTING THE DVD TRAY MANUALLY

1. Insert a Screwdriver or similar object into the Eject hole.

2. Press it gently, and then pull the Tray fully out.

Fig. 4

5.1.3. GROUNDING FOR ELECTROSTATIC BREAKDOWN

Prevention

1. Human body grounding

Use the antistatic wrist strap to discharge the static electricity from your body.

2. Work table grounding

Put a conductive material (sheet) or steel sheet on the area where the optical pickup is placed and ground the sheet.

Caution:

The static electricity of your clothes will not be grounded through the wrist strap. So take care not to let your clothes touch the optical pickup.

Fig. 3

PV-20DF25 / PV-27DF25 / PV-27DF5 / PV-20DF25-K / PV-27DF25-K

5.1.5. DVD SERVICE MODE

This unit has a Self-Diagnostic function which detects a problem or malfunction within the unit and displays it on the TV screen.

5.1.5.1. How to enter DVD Service Mode

1. Set the unit to DVD mode.

2. Press and hold the STOP, SKIP+, and VOL- buttons on the unit together for over 5 seconds. The adjustment overlay will appear on the TV screen.

Fig. 5-1

3. Press the DISPLAY key on the remote control to enter DVD Service Mode I.

defective by checking the value of JITTER and the value of LASER (current).

Fig. 5-2

4. Press the LEFT or RIGHT key on the remote again to enter DVD Service Mode II.

Fig. 5-3

Note:

a. After replacing the DVD Unit, press the CLEAR key

on the remote in this mode. The total elapsed "Disc Motor on" time (in hours/minutes) will be cleared to

b. If 01 or 02 is always displayed in 9 DM STATUS,

replace the DVD Unit because the Disc Motor is defective.

5. To confirm the value of JITTER and the value of LASER (current), insert the DVD Test Disc into the DVD Unit.

6. To release from this mode, turn off the power.

5.1.5.2. Troubleshooting hint (standard)

for this mode

It can be determine whether the DVD Mechanism Unit is

5.1.6. SERVICE POSITION

CAUTION:

1. HOT CIRCUIT (Primary circuit) exists on the Main C.B.A.

Use extreme care to prevent accidental shock when servicing.

2. Before connecting the AC plug, be sure to confirm the connection between the Connector P502 on the Deflection C.B.A. and P851/P852 on the Main C.B.A. Otherwise, some electrical parts may be damaged due to a sudden power surge.

PV-20DF25 / PV-27DF25 / PV-27DF5 / PV-20DF25-K / PV-27DF25-K

5.1.6.1.2. Service Position (2)

1. Remove the Rear Cover. Then, turn the DVD Ass´y to the right.

2. Connect the DVD Main C.B.A. using the Extension Cable 16P.

5.1.6.1. How to obtain Service Position for Combination TV/DVD models

To obtain these Service Positions, the 2 Extension Cables 13P (LSUA0047) and 16P (LSUA0048) are necessary.

5.1.6.1.1. Service Position (1)

1. Remove the Rear Cover. Then, pull the DVD Ass´y out and

place it upright.

Fig. 6-2

5.1.6.1.3. Service Position (3)

1. Remove the Rear Cover. Then, pull out the DVD Ass´y.

2. Place the Deflection C.B.A. and the Main C.B.A. upright. Then, connect them using the Extension Cable 13P.

Fig. 6-1

Fig. 6-3

PV-20DF25 / PV-27DF25 / PV-27DF5 / PV-20DF25-K / PV-27DF25-K

5.1.7. HOT CIRCUIT

Primary circuit exists on the Main C.B.A. This circuit is identified as " HOT " on the C.B.A. and in the

Service Manual. Use extreme care to prevent accidental shock when servicing.

5.1.8. F.F.C. CONNECTION NOTE

5.1.8.1. F.F.C. between the DVD Unit (DVD Main C.B.A.) and the Main C.B.A.

Be careful with the direction of F.F.C. to connector as shown.

Fig. 7

5.1.9. WIRE AND LEAD POSITION DIAGRAM

PV-20DF25 / PV-27DF25 / PV-27DF5 / PV-20DF25-K / PV-27DF25-K

Fig. 8

PV-20DF25 / PV-27DF25 / PV-27DF5 / PV-20DF25-K / PV-27DF25-K

5.1.10. HOW TO RESET ALL

COMBINATION TV/DVD MEMORY FUNCTIONS

To reset (clear) the select language, channel auto set and set clock functions to their initial power on condition, hold down the PLAY and SKIP- buttons of operation panel on the unit together for more than 5 seconds.

Power will shut off.

5.1.11. HOW TO CONFIRM AUTO CLOCK

SET FEATURE

1. Connect an RF cable from the output of one unit to the input

of the test unit.

2. Select corresponding RF channels.

3. Playback a recording of P.B.S. channel including clock set

data and confirm this feature.

5.1.12. VARIABLE VOLTAGE ISOLATION

TRANSFORMER

An Isolation Transformer should always be used during the servicing of Combination TV/DVD whose chassis is not isolated from the 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 Combination TV/DVD from being damaged by accidental shorting that may occur during servicing.

Also, when troubleshooting the above type of Power Supply Circuit, a variable isolation transformer is required in order to increase the input voltage slowly.

5.1.13. SPECIAL NOTE

All integrated circuits and many other semiconductor devices are electrostatically sensitive and therefore require the special handling techniques described under the "ELECTROSTATICALLY SENSITIVE (ES) DEVICES" section of this service manual.

5.1.14. MODEL NO. IDENTIFICATION

MARK

Use Marks shown in the chart below to distinguish the different models included in this Service Manual.

PV-20DF25 / PV-27DF25 / PV-27DF5 / PV-20DF25-K / PV-27DF25-K

6 DISASSEMBLY/ASSEMBLY PROCEDURES

6.1. CABINET SECTION

6.1.1. Disassembly Flowchart

Perform all disassembly procedures in the order described in the "Disassembly Flowchart" shown below. When reassembling, use the reverse procedure.

CAUTION:

1. Disconnect AC plug before disassembly.

Fig. D1

PV-20DF25 / PV-27DF25 / PV-27DF5 / PV-20DF25-K / PV-27DF25-K

Fig. D2

PV-20DF25 / PV-27DF25 / PV-27DF5 / PV-20DF25-K / PV-27DF25-K

Fig. D3

PV-20DF25 / PV-27DF25 / PV-27DF5 / PV-20DF25-K / PV-27DF25-K

Fig. D4

6.1.1.1. Notes in chart

1. Removal of DVD Ass’y

PV-20DF25 / PV-27DF25 / PV-27DF5 / PV-20DF25-K / PV-27DF25-K

Fig. D5

2. Removal of Color Picture Tube Unit Place the Unit face down on a soft cloth before removing the Color Picture Tube Unit.

3. Removal of DVD Sub C.B.A. a. Remove solder portions "a, b, c, d, e, f, g, h, i, j" on the DVD Sub C.B.A. b. Remove the DVD Sub C.B.A. while releasing the Locking Tab.

Installation of DVD Main C.B.A. and DVD Sub C.B.A.

a. Confirm that the Lever A is positioned as shown, and install the DVD Sub C.B.A. with the Locking Tab and 2 bosses. b. Install the DVD Main C.B.A. with the Locking Tab and the rib. c. Pass the leads through the slots A and B. d. Solder portions "a, b, c, d, e, f, g, h, i, j, k" on the C.B.A.

Note:

Solder portions "h" and "i" while pushing down the DVD Sub C.B.A. securely. e. Connect the F.F.C.s to Connectors P8901 on the DVD Main C.B.A. f. Tighten the 2 Screws (520).

PV-20DF25 / PV-27DF25 / PV-27DF5 / PV-20DF25-K / PV-27DF25-K

Fig. D6

7 ADJUSTMENT PROCEDURES

7.1. SERVICE FIXTURES AND TOOLS

PV-20DF25 / PV-27DF25 / PV-27DF5 / PV-20DF25-K / PV-27DF25-K

7.2. ELECTRICAL ADJUSTMENT

NOTE: Following Adjustments have been preadjusted at factory and

are not required.

· Purity Adjustment

· Convergence Adjustment

7.2.1. TEST EQUIPMENT

To do all of these electrical adjustments, the following equipment is required.

1. Dual-Trace Oscilloscope Voltage Range: 0.001 V to 50 V/Div. Frequency Range: DC to 50 MHz Probes: 10:1, 1:1

2. NTSC Video Pattern Generator

3. Isolation Transformer (Variable)

4. Degaussing Coil

5. White Pattern Generator

7.2.3. EVR (Electronic Variable Register) ADJUSTMENT WITH THE REMOTE CONTROL

This unit has electronic technology using I2C Bus concept. The following control functions are adjusted by using "On

Screen Displays" and the remote control instead of adjusting mechanical controls (VR).

7.2.2. HOW TO READ THE ADJUSTMENT PROCEDURES

Fig. E1

7.2.4. EVR ADJUSTMENT ITEM

The following Items need to be adjusted for EVR adjustment.

· SUB CONTRAST ADJUSTMENT

· FOCUS, SCREEN, CUT OFF, DRIVE ADJUSTMENT

· SUB COLOR/SUB TINT ADJUSTMENT

· DEFLEC TION DISTORTION CORRECTION

ADJUSTMENT

· WHITE BALANCE ADJUSTMENT

· SUB BRIGHTNESS ADJUSTMENT

7.2.5. HOW TO ENTER EVR ADJUSTMENT MODE

Press and hold STOP, SKIP + and VOL - buttons on the unit together over 5 seconds.

The adjustment overlay will appear to Enter EVR adjustment mode.

Fig. E2-1

7.2.5.1. How to adjust:

1. Press UP/DOWN key on the remote control to

select control function to be adjusted.

Important Note:

Make a note of the original value of the controls before modifying in case the wrong control is adjusted.

2. Press RIGHT/LEFT that the shaded area moves to the value.

3. Press UP/DOWN key on the remote control to adjust the value of the selected control.

key on the remote control so

Fig. E2-2

PV-20DF25 / PV-27DF25 / PV-27DF5 / PV-20DF25-K / PV-27DF25-K

7.2.5.3. HOW TO ENTER SERVICE MODE

1. Set the unit to TV Mode.

2. Enter EVR adjustment mode.

3. Press DISPLAY key on the remote control for collapse scan.

Note:

Before pressing DISPLAY key on the remote control for collapse scan, select the desired control function and move the shaded area to the value for adjustments you will proceed.

Fig. E2-6

Fig. E2-3

Note:

You can select a desired channel by using the numbered keys on the remote control in EVR adjustment mode.

4. Press RIGHT/LEFT that the shaded area moves to the control function.

5. Press UP/DOWN key on the remote control to select a control function for the next adjustment if necessary.

key on the remote control so

Fig. E2-4

Fig. E2-5

7.2.5.4. How to release from Service Mode:

Press DISPLAY key again on the remote control.

7.2.5.2. How to release from EVR Adjustment Mode:

Press and hold STOP, SKIP + and VOL - buttons on the unit together over 5 seconds again or press the POWER button OFF to release EVR adjustment mode. The adjusted value will be written to Memory IC (IC6004).

PV-20DF25 / PV-27DF25 / PV-27DF5 / PV-20DF25-K / PV-27DF25-K

7.2.6. SUB CONTRAST ADJUSTMENT

Purpose: To set the optimum sub contrast level. Symptom of

Misadjustment:

Test Point : TP49 (CRT C.B.A.) Adjustment : SUB CONTRAST (EVR), Specification : Refer to descriptions below.

Input : Video Input Jack,

Mode : STOP Equipment : Oscilloscope,

1. Supply a Crosshatch Pattern Signal to the Video Input Jack.

2. Connect the Oscilloscope to TP49 on the CRT C.B.A. (Use TP47 for GND.)

3. Select SUB BRIGHT in EVR adjustment mode. Then, after making a note of the original value, adjust to the (C0).

4. Select SUB CONTRAST in EVR adjustment mode and adjust so that the level A is (3.0 V[p-p]±0.1 V[p-p]: For

model with 20 inch CRT), or (3.15 V[p-p]±0.1 V[p-p]: For model with 27 inch CRT).

5. Select SUB BRIGHT in EVR adjustment mode and reset to the original value.

The picture is too dark or too light.

Crosshatch Pattern Signal 1 V[p-p] (75 Ω terminated)

NTSC Video Pattern Generator

7.2.7. FOCUS, SCREEN, CUT OFF, DRIVE ADJUSTMENT

Purpose: To set the optimum Screen. Symptom of

Misadjustment:

Test Point : TP50 (CRT C.B.A.) Adjustment : FOCUS CONTROL

Specification : Refer to descriptions below.

Input : Video Input Jack,

Mode : STOP Equipment : Oscilloscope,

1. Supply a Crosshatch Pattern Signal to the Video Input Jack.

2. Adjust the FOCUS CONTROL on the Flyback Transformer

so that the "a" and "b" are the sharpest.

The picture is will be an improper screen color mix.

(Flyback Transformer), SCREEN CONTROL (Flyback

Transformer), SUB BRIGHT (EVR), G DRIVE (EVR), B DRIVE (EVR), R CUT-OFF (EVR), G CUT-OFF (EVR), B CUT-OFF (EVR)

Crosshatch Pattern Signal, Monoscope Pattern Signal

NTSC Video Pattern Generator

Fig. E3

Fig. E4-1

3. Supply a Monoscope Pattern Signal to the Video Input

Jack.

4. Connect the Oscilloscope to TP50 on the CRT C.B.A.

(Use TP47 for GND.)

5. Select SUB BRIGHT and move the shaded area to the

value in EVR adjustment mode.

6. Turn the SCREEN CONTROL on the Flyback Transformer

fully counterclockwise.

7. Press DISPLAY key on the remote control for collapse

scan. (Refer to "HOW TO ENTER SERVICE MODE.")

8. Adjust SUB BRIGHT in EVR adjustment mode so that the

level A is (170 VDC±5 VDC: For model with 20 inch CRT), or (185 VDC±5 VDC: For model with 27 inch CRT).

Fig. E4-2

9. Turn the SCREEN CONTROL on the Flyback Transformer clockwise carefully and stop at the point where any color is first observed.

10. In EVR adjustment mode, select the two colors not observed in step 8 from the following control functions (R CUT-OFF, G CUT-OFF, B CUT-OFF) and adjust so that the horizontal line becomes white.

For example, if the horizontal line appeared red in step 8, select and adjust the B CUT-OFF and G CUT-OFF. (See NOTE)

11. Press DISPLAY key on the remote control again to return for full frame scan.

12. Select SUB BRIGHT in EVR adjustment mode and adjust so that the picture has adequate brightness.

13. Select G DRIVE and B DRIVE in EVR adjustment mode and adjust so that the entire screen is white.

Note:

Before pressing DISPLAY key on the remote control for collapse scan, select the desired control function and move the shaded area to the value.

PV-20DF25 / PV-27DF25 / PV-27DF5 / PV-20DF25-K / PV-27DF25-K

7.2.8. SUB COLOR/SUB TINT ADJUSTMENT

Purpose : To set the standard color phase. Symptom of

Misadjustment :

Test Point : TP49 (CRT C.B.A.) Adjustment : SUB COLOR (EVR),

Specification : Refer to descriptions below.

Input : Video Input Jack,

Mode : STOP Equipment : Oscilloscope,

1. Supply the Rainbow Color Bar signal to Video Input Jack.

2. Connect the Oscilloscope to TP49 on the CRT C.B.A.

3. Select SUB BRIGHT in EVR adjustment mode. Then, after

making a note of original value, adjust to the (C0).

4. Select SUB TINT in EVR adjustment mode and adjust so

that level A and B should be equal in amplitude.

Color phase will be shifted.

SUB TINT (EVR),

Rainbow Color Bar

NTSC Video Pattern Generator

Fig. E5-1

5. Select SUB COLOR in EVR adjustment mode and adjust

which higher level that level C is 1.40 V[p-p]±0.15 V[p-p].

Fig. E5-2

PV-20DF25 / PV-27DF25 / PV-27DF5 / PV-20DF25-K / PV-27DF25-K

6. Select SUB TINT in EVR adjustment mode and increase level B 1 clicks above the same level.

Fig. E5-3

7. Select SUB BRIGHT in EVR adjustment mode and reset to the original value.

7.2.9. DEFLECTION DISTORTION CORRECTION ADJUSTMENT

Purpose : To set the optimum picture. Symptom of

Misadjustment :

Test Point : ---------Adjustment : V POSITION (EVR),

Specification : Refer to descriptions below.

Input : Video Input Jack,

Mode : STOP Equipment : NTSC Video Pattern Generator

The picture is distortion.

V SIZE (EVR), H-CENTER (EVR), (For model with 27 inch CRT) R763 (Deflection C.B.A.), R753 (Deflection C.B.A.), R766 (Deflection C.B.A.)

Crosshatch Pattern Signal, Monoscope Pattern Signal

1. Supply a Crosshatch Pattern Signal to the Video Input Jack.

2. Confirm that the Horizontal Center Line is within the limits of

Fig. E6-1

3. (For model with 27 inch CRT)

Adjust R763 so that vertical lines should be almost straight.

4. (For model with 27 inch CRT)

Adjust R753 so that vertical lines at Left edge and Right edge should be almost straight.

5. Supply a Monoscope Pattern Signal to the Video Input

Jack.

6. Select V POSITION in EVR adjustment mode and adjust

Horizontal Center Line is within the limits of A.

Fig. E6-2

7. Select V SIZE in EVR adjustment mode and adjust so that the top 4th line is just in view, and that the Bottom edge is between the 9th line and the 11th line.

8. Select H-CENTER in EVR adjustment menu and adjust so that B is approximately equal to width C.

9. (For model with 27 inch CRT) Adjust R766 so that the left 4th line is just in view.

10. Supply a Crosshatch Pattern Signal to the Video Input Jack. Then, confirm that the picture is no distortion.

PV-20DF25 / PV-27DF25 / PV-27DF5 / PV-20DF25-K / PV-27DF25-K

7.2.10. WHITE BALANCE ADJUSTMENT

Purpose: To set the standard white level for each

color temperature.

Symptom of Misadjustment :

Test Point : TP50 (CRT C.B.A) Adjustment : FOCUS CONTROL

Specification : Refer to descriptions below.

Input : Video Input Jack,

Mode : STOP Equipment : NTSC Video Pattern Generator,

1. Supply a Monoscope Pattern Signal to the Video Input Jack.

2. Connect the Oscilloscope to TP50 on the CRT C.B.A. (Use TP47 for GND.)

3. Select SUB BRIGHT and move the shaded area to the value in EVR adjustment mode.

4. Adjust the FOCUS CONTROL on the Flyback Transformer so that the "a" and "b" are the sharpest.

White becomes bluish or reddish.

(Flyback Transformer), SCREEN CONTROL (Flyback

Transformer), SUB BRIGHT (EVR), G DRIVE (EVR), B DRIVE (EVR), R CUT-OFF (EVR), G CUT-OFF (EVR), B CUT-OFF (EVR)

Monoscope Pattern Signal, White Pattern Signal

White Pattern Generator, Oscilloscope

Fig. E7-1

5. Turn the SCREEN CONTROL on Flyback Transformer fully counterclockwise.

6. Press DISPLAY key on the remote control for collapse scan. (Refer to "HOW TO ENTER SERVICE MODE.")

7. Adjust SUB BRIGHT in EVR adjustment mode so that the level A is 175 VDC±5 VDC.

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