Panasonic PVQ-130W, PVQ-1300WA Schematic

ORDER NO. MKE0008107C1

Combination VCR

PVQ-130W

PVQ-130WA

PVQ-1300W

PVQ-1300WA

SPECIFICATIONS

1. SAFETY PRECAUTIONS

GENERAL GUIDELINES

1. IMPORTANT SAFETY NOTICE There are special components used in this equipment which are important for safety. These parts are marked by 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.

in the Schematic Diagrams, Circuit Board

2. An Isolation Transformer should always be used during the servicing of Combination VCR 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 VCR 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

115 V

ΩΩΩΩ

1 k

(Cold chassis ground)

24 V

ΩΩΩΩ

180

(Cold chassis ground)

15 V

ΩΩΩΩ

110

(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 25.0 kV are 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.

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 M

ΩΩΩΩ

and 12 M

ΩΩΩΩ

. When the exposed metal does not

have a return path to the chassis, the reading must be infinity.

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

3. Use an AC voltmeter, with 1 k 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 customer.

ΩΩΩΩ

, 10 W resistor, in parallel with a 0.15

ΩΩΩΩ

/V or more sensitivity, to measure the potential

Figure 1

µµµµ

F capacitor, between each

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 25.0 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 23.5 kV±1.5 kV. 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.

HORIZONTAL OSCILLATOR DISABLE CIRCUIT TEST SERVICE WARNING : The test must be made as a final check before set is returned to the customer. CONFIRMATION OF X-RAY MOVEMENT

1. Turn off TV set.

2. Connect the circuit below between TP1209 and TP1208.

Figure 2

3. Turn on DC Power, 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 the voltage to DC Power.

5. If this does not occur even when getting down the voltage of DC Power to 0 V, it means that X-ray protect circuit is not operating. Further confirmation and repair is required.

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 +21.9 V is not present at that point when 120 V AC is applied, find the cause. Check R503, R5505, C5507, C513 and D503.

3. Carefully check above specified parts and related circuits and parts. When the circuit is repaired, try the horizontal oscillator disable circuit test again.

CIRCUIT EXPLANATION

HORIZONTAL OSCILLATOR DISABLE CIRCUIT The positive DC voltage, supplied from the D503 cathode for monitoring high voltage, is applied to the IC5301 Pin11 through R503 and R5504. Under normal conditions, the voltage at IC5301 Pin 11 is less than approx 3 V. If the high voltage at Flyback Tr 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 Pin11 through R503 and R5504. Due to the increased voltage at IC5301 Pin11, the horizontal oscillator frequency increases, the picture goes out of horizontal sync, the beam current decreases and the picture becomes dark in order to keep X-radiation under specification.

Figure 3

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 antistatic solder removal device. Some solder removal devices not classified as "antistatic (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).

"NOTE to CATV system installer : 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. OPERATION GUIDE

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. A 4 digit for fault code and communication for I2C bus code will be displayed on 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 FF and REW buttons on unit together for over 3 seconds.

Fig. 1-1

2. TV power goes on and the unit goes into service mode. 4 digit for fault code and communication for I2C bus code will be displayed.

Fig. 1-2

Fig. 1-3

Fig. 1-4

Fig. 1-5

3. Press any operation button except for POWER on either the unit, or the remote to detect that a key has been pressed. The 1st digit changes to "0" only when key is detected.

Fig. 1-6

Note:

When 1 to 4 listed in Lock code occurs, the VCR stops and all VCR function buttons except for power become non-operational.

5.1.2. SERVICE POSITION

5.1.2.1. Service Position

CAUTION:

HOT CIRCUIT (Primary circuit) exists on the TV/VCR Main C.B.A. Use extreme care to prevent accidental shock when servicing.

5.1.2.1.1. Service Position (1)

Fig. 2-1

5.1.2.1.2. Service Position (2)

Fig. 2-2

Note:

1. When recording in Service Position (2), short the S-Tab SW. Pins on foil side of TV/VCR Main C.B.A. to turn this SW. on.

Fig. 2-3

2. When disassembling/assembling, refer to "CABINET SECTION" in DISASSEMBLY/ASSEMBLY PROCEDURES.

5.1.3. HOT CIRCUIT

Primary circuit exists on the TV/VCR 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.

5.1.4. SERVICE MODE

In order to inhibit detection of the Supply & Takeup Photo Transistors, Reel Sensor, and Cylinder Lock, place a jumper between TP6001 and GND. In this mode, Mechanism movement can be confirmed. When removing Cassette Up Ass'y, it can be confirmed without a cassette. To release from this mode, remove the jumper between TP6001 and GND.

5.1.5. CAUTION FOR INSTALLATION OF VCR UNIT

CAUTION: Opener Lever may be damaged when VCR Unit is installed, with Cassette Door-Lid and Opener Lever of Cassette Up Ass'y set incorrectly.

Install the VCR Unit as follows:

1. Swing the Cassette Door-Lid all the way open until the Cassette Door tab clears the Opener Lever.

2. Make sure that all guide tabs are aligned properly. Then, press the VCR Unit straight in.

Fig. 3

5.1.6. HOW TO INITIALIZE MEMORY IC

After the Memory IC (IC6004) or TV/VCR Main C.B.A. is replaced, be sure to set the Default value to Memory IC as shown in "Memory IC Reference Table" below.

1. Press and hold STOP, PLAY, and VOL DOWN buttons on the unit together over 5 seconds with no cassette inserted. The adjustment overlay will appear to Enter EVR Adjustment mode.

Fig. 4-1

2. Set the Default value of all Control functions using a remote control as shown in "Memory IC Reference Table."

Note:

For Selecting Control functions and setting Default value, refer to "

HOW TO ENTER EVR ADJUSTMENT MODE" and "HOW TO ENTER EVR PG SHIFTER ADJUSTMENT MODE" in ELECTRICAL ADJUSTMENT procedures.

Fig. 4-2

3. Press and hold STOP, PLAY, and VOL DOWN buttons on the unit together over 5 seconds again or press the POWER button OFF to release EVR Adjustment Mode. The Default value will be written to Memory IC (IC6004).

4. Perform all EVR Adjustments. (Refer to "

EVR (Electronic Variable Register) ADJUSTMENT WITH THE REMOTE CONTROL" in ELECTRICAL ADJUSTMENT

procedures.)

5.1.7. METHOD FOR LOADING/UNLOADING OF MECHANISM

5.1.7.1. (Manual Method)

Turn the Loading Gear clockwise (for loading) or counterclockwise (for unloading) using needlenose pliers etc.

Note:

Do not use this method if Mechanism is jammed or locked.

Fig. 5-1

5.1.7.2. (Electrical Method)

Apply +10.0 V DC Power Supply to the Loading Motor terminals. Loading DC + to Portion "a," DC - to Portion "b" Unloading DC - to Portion "a," DC + to Portion "b"

CAUTION:

Before applying DC Power Supply, be sure to disconnect the Motor Leads from the Connector P2503. Otherwise, the Loading Motor Drive IC (IC2501) may be damaged.

Fig. 5-2

When loading without a cassette, push Portion "a" on the Holder Unit of Cassette Up Ass'y so that the Lever clear the First Tab and Second Tab.

Fig. 5-3

5.1.8. HOW TO REMOVE A JAMMED TAPE

CAUTION: Wiper Arm Unit may be damaged or its spring may be out of place when the jammed tape is removed by force.

Remove a jammed tape as follows:

5.1.8.1. Manual Method

When a tape jam is encountered, check the tape loading condition and use the

following procedure to remove a tape jam.

Fig. 6-1

5.1.8.1.1. Method -1:

1. Move the Pinch Roller Unit out by unhooking the Pin of Pinch Arm Unit so that the Pinch Roller is separated from the Capstan Rotor Unit shaft.

Fig. 6-2

2. Remove the tape from the tape path.

3. Rewind the tape into the cassette by rotating the Center Clutch Unit counterclockwise.

4. Unhook Spring (A) of the Drive Rack Arm.

5. Remove Screw (A).

6. Lift the Cassette Up Ass'y. While pulling the Cassette Up Ass'y out far enough so that it clears the Drive Rack Arm, slide the Drive Rack Unit as indicated by the arrow to remove the cassette tape from the Cassette Up Ass'y.

7. Check the cause of mechanical trouble and repair.

Fig. 6-3

5.1.8.1.2. Method -2:

1. Rotate Loading Motor counterclockwise with needlenose pliers, etc. so that the Pinch Roller is separated from the shaft of the Capstan Rotor Unit.

2. Perform Step 2 through Step 7 of Method -1.

5.1.8.1.3. Method -3:

1. Perform Step 2 through Step 7 of Method -1.

Note:

After repairing mechanical trouble, make sure that all gear alignments are correct, especially the Wiper Arm Unit and Drive Rack Unit of Cassette Up Ass'y. (Refer to "

EJECT Position Confirmation" in DISASSEMBLY/ASSEMBLY PROCEDURES.)

5.1.8.2. Electrical Method

Electrical method can only be performed when the mechanism is moved by rotating the Loading Gear. CAUTION:

1. Before applying DC Power Supply, be sure to disconnect the Motor Leads from the Connector P2503. Otherwise, the Loading Motor Drive IC (IC2501) may be damaged.

2. If loading does not start in approx. 2 seconds after DC Power Supply is applied, DO NOT continue to apply DC Power Supply. Instead, perform "

Manual Method."

1. Be sure to disconnect the Motor Leads from the Connector P2503.

2. Apply +10.0 V DC Power Supply to the Loading Motor terminals.

3. When the Loading Posts reach the fully unloaded position, remove the Power Supply.

Fig. 7

4. Rewind the tape into the cassette by turning the Center Clutch Unit counterclockwise.

5. Eject the cassette by applying +10.0 V DC Power Supply again.

5.1.9. VCR Test Mode

High Voltage is inhibited by connecting Jumper J801 on the TV/VCR Main C.B.A., however, it is possible to check the VCR even when CRT C.B.A. and Anode Cap are removed.

5.1.10. WIRE AND LEAD POSITION DIAGRAM

Fig. 8

5.1.11. DEFEATING THE AUTO TRACKING

To defeat the Auto Tracking Function, place the instrument in the STOP mode and place a jumper between TP6003 and TP6009 on the TV/VCR Main C.B.A. The tracking will be placed in the neutral position.

5.1.12. HOW TO SET TRACKING TO THE NEUTRAL POSITION

Ejecting the cassette tape and then reinserting it will reset the tracking to the Neutral position.

5.1.13. BLACK SCREWS ON THE CHASSIS

Black Screws are used on the Mechanism Chassis to identify screws that require adjustment.

5.1.14. HOW TO RESET ALL COMBINATION VCR MEMORY FUNCTIONS

To reset (clear) the select language, channel auto set and set clock functions to their initial power on condition (power on, no cassette inserted), hold down the PLAY and FF buttons on the unit together for more than 5 seconds. Power will shut off.

5.1.15. 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.

5.1.16. VARIABLE VOLTAGE ISOLATION TRANSFORMER

An Isolation Transformer should always be used during the servicing of Combination VCR 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 VCR 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.

5.1.17. 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.

5.1.18. REPLACEMENT PROCEDURE FOR LEADLESS (CHIP)

COMPONENTS

The following procedures are recommended for the replacement of the leadless components used in this unit.

1. Preparation for replacement

A. Soldering Iron

Use a pencil-type soldering iron that uses less than 30 watts.

B. Solder

Eutectic Solder (Tin 63%, Lead 37%) is recommended.

C. Soldering time

Do not apply heat for more than 4 seconds.

D. Preheating

Leadless capacitor must be preheated before installation. -(266°F ~ 302°F)

(130°C ~150°C) for about two minutes. Note: A. Leadless components must not be reused after removal. B. Excessive mechanical stress and rubbing of the component electrode must be

avoided.

2. Removing the leadless component Grasp the leadless component body with tweezers and alternately apply heat to both electrodes. When the solder on both electrodes is melted, remove the leadless component with a twisting motion. Note: A. Do not attempt to lift the component off the board until the component is

completely disconnected from the board by a twisting action.

B. Be careful not to break the copper foil on the printed circuit board.

Fig. 9-1

3. Installing the leadless component A. Presolder the contact points on the circuit board.

Fig. 9-2

B. Press the part downward with tweezers and solder both electrodes as shown

below.

Fig. 9-3

Note:

Do not glue the replacement leadless component to the circuit board.

5.2. IC, TRANSISTOR AND CHIP PART INFORMATION

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