Panasonic Quasar Omnivision PV-V4021-K User manual

ORDER NO. MKE0101000C1
B3
Video Cassette Recorder
PVQ-V201 / PV-V4021 / PV-V4021-K / VHQ-401 / VHQ-41M / PV-
V4511 / PV-V4521 / PV-V4521A / PV-V4521-K / VHQ-451 / PV-
V4611
SPECIFICATIONS

1. MODEL NUMBER INDICATION
Use Marks shown in the chart below to distinguish the different models included in this Service
Manual.
The Model number is indicated on the Model No. Label which is located on the rear side of the Cabinet.
Differences between PV-V4521 and PV-V4521A are as below.
- Cylinder Unit (Ref. No. 11)
- Grounding Plate Unit (Ref. No. 57)
- Screw (Ref. No. 430)
- Flexible Flat Cable (Ref. No. 718)
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- Main C.B.A. (Ref. No. E10)
When ordering these, be sure to confirm the model number printed on the Model No. Label and order
the proper parts according to the replacement parts list.
2. 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 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 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 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 VCR from being damaged by accidental shorting that
may occur during servicing.
3. When servicing, observe the original lead dress. 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 shields are properly installed.
5. 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. Measure the resistance value, with an ohmmeter, between the
jumpered AC plug and each exposed metallic cabinet part on the
equipment such as screwheads, connectors, control shafts, etc. When
the exposed metallic part has a return path to the chassis, the reading
should be between 1 M and 5.2 M . When the exposed metal does
not have a return path to the chassis, the reading must be infinity.
LEAKAGE CURRENT HOT CHECK
(See figure 1.)
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1. Plug the AC cord directly into the AC outlet. Do not use an isolation
transformer for this check.
2. Connect a 1.5 k , 10 W resistor, in parallel with a 0.15 F 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 k /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 or 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
a shock hazard, and the equipment should be repaired and rechecked
before it is returned to the customer.
Figure 1
3. PREVENTION OF ELECTRO-STATIC 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, some field-effect transistors and 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 by
touching a known earth ground. Alternatively, obtain and wear a
commercially available discharging ESD wrist strap, which should
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remove electrostatic charge 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 820-22 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
(With clock model in F.I.P.)
Simplified Self-Diagnostic System facilitates finding the cause of the fault. A 4 digit fault code will be
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displayed in F.I.P.
The Simplified Fault finding data is stored in the Memory IC (IC6005). This data is cleared after it is
displayed, and then the POWER button is pressed back on.
1. With power turned off, press VCR/TV button on VCR (for over 3
seconds if VCR is not in shut off condition).
Fig. 1-1
2. Fault code (4 digit number) will be displayed in F.I.P. as shown.
Fig. 1-2
Fig. 1-3
Fig. 1-4
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Fig. 1-5
Fig. 1-6
3. While pressing VCR/TV button on VCR with power turned off, press
any operation button on either VCR, or remote to detect that a key has
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been pressed.
The 1st digit changes to "0" only when key is detected.
Fig. 1-7
4. When 1 to 4 listed in Lock code occurs, Lock data will be stored in the
EEPROM IC (Current data, Last Lock data, and the Last Lock data
before last). Lock data displayed in F.I.P. can be changed by pressing
CH DOWN button.
Fig. 1-8
Note:
1. Lock data will be kept after the AC Cord is unplugged.
2. When 1 to 4 listed in Lock code occurs for the first time, the VCR does
not go into VCR shut-off condition. If it occurs again within a minute,
the VCR goes into VCR shut-off condition. Then, the VCR stops and all
VCR function buttons except for power become non-operational.
(Without clock model in F.I.P.)
Simplified Self-Diagnostic System facilitates finding the cause of the fault. LED will light up or flash in
F.I.P.
The Simplified Fault finding data is stored in the Memory IC (IC6005). This data is cleared after it is
displayed, and then the POWER button is pressed back on.
1. With power turned off, press VCR/TV button on VCR (for over 3
seconds if VCR is not in shut off condition).
Fig. 2-1
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2. Fault indication will be displayed in F.I.P. as shown.
Fig. 2-2
FIg. 2-3
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3. When Lock indication occurs, Lock data will be stored in the EEPROM
IC (Current data, Last Lock data, and the Last Lock data before last).
Lock data displayed in F.I.P. can be changed by pressing CH DOWN
button.
Fig. 2-4
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Note:
1. Lock data will be kept after the AC Cord is unplugged.
2. When Lock indication occurs for the first time, the VCR does not go
into VCR shut-off condition. If it occurs again within a minute, the VCR
goes into VCR shut-off condition. Then, the VCR stops and all VCR
function buttons except for power become non-operational.
5.1.2. USAGE SCREEN MODE
Function displayed on the TV monitor:
- the total elapsed "Power on" time (in days)
- the total elapsed "Cylinder rotation" time (in hours)
1. With power turned on and no cassette, press VCR/TV button on VCR
and 7 key on remote together.
The USAGE SCREEN will be displayed on the TV Monitor.
Fig. 3
Note:
1. After replacing the Cylinder Unit, press COUNTER RESET button on
remote in this mode. Only Total elapsed "Cylinder rotation" time (in
hours) will be cleared to 0.
2. To release from Usage Screen Mode, press any operation button on
VCR or insert a cassette tape in this mode. The VCR will return to
normal operation mode.
5.1.3. EEPROM IC (IC6005), MAIN C.B.A. REPLACEMENT NOTE
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After replacing EEPROM IC (IC6005) or Main C.B.A., be sure to perform the "PG SHIFTER
ADJUSTMENT" in ELECTRICAL ADJUSTMENT procedures.
5.1.4. SERVICE POSITION
5.1.4.1. Service Position
CAUTION:
HOT CIRCUIT (Primary circuit) exists on the Main C.B.A.
Use extreme care to prevent accidental shock when servicing.
5.1.4.1.1. Service Position (1)
Fig. 4-1
5.1.4.1.2. Service Position (2-1)
(Model: A, B, C, D, E, F, G, H, I, J, K, L)
Fig. 4-2-1
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5.1.4.1.3. Service Position (2-2)
(Model: M, N)
Fig. 4-2-2
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Note:
1. It is possible that the S-Tab SW. may not work correctly in Service
Position (2-1), (2-2). (Recording can not be done). In this case, short
the S-Tab SW. Pins on the foil side of the Main C.B.A. to turn this SW.
on.
Fig. 4-3
2. Place the tape between the Cassette Up Ass’y and Main C.B.A. to get a
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stability.
3. When disassembling/assembling, refer to "CABINET SECTION" in
DISASSEMBLY/ASSEMBLY PROCEDURES.
5.1.5. 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.
5.1.6. SERVICE MODE
In order to inhibit detection of the Supply & Takeup Photo Transistors, Reel Sensor, and Cylinder
Lock, press and hold VCR/TV button and CH DOWN buttons on VCR together over 5 seconds in power
off condition.
Fig. 5-1
The power comes on and the unit goes into service mode.
In this mode, Mechanism movement can be confirmed. When removing Cassette Up Ass’y, it can be
confirmed without a cassette.
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To release from this mode, press POWER button off or disconnect AC Plug.
5.1.7. TRACKING CENTER MODE (TRACKING FIX AT CENTER)
Insert the Cassette tape. Set the unit into Service Mode. Play back the Cassette tape. Press PLAY
button in Play back mode. "TRACKING CENTER" will be displayed on the TV monitor.
In this mode, the tracking is fixed at center. (Auto tracking and manual tracking functions are not
operational.)
Fig. 5-2
To release from this mode, press PLAY or STOP button.
5.1.8. CAUTION FOR INSTALLATION OF FRONT PANEL ASS’Y
CAUTION:
Opener Lever may be damaged when Front Panel Ass’y is installed, with
Cassette Door-Lid of Front Panel Ass’y and Opener Lever of Cassette
Up Ass’y set incorrectly.
Install the Front Panel Ass’y 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 locking tabs are aligned properly. Then, press the
Front Panel straight in.
Fig. 6
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5.1.9. METHOD FOR LOADING/UNLOADING OF MECHANISM
5.1.9.1. (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. 7-1
5.1.9.2. (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 cut the Motor Leads with a
cutter, etc.
Otherwise, the Loading Motor Drive IC (IC2501) may be damaged.
When reconnecting the Motor Leads, solder at below / 320 °C for less
than 3 seconds.
Fig. 7-2
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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. 7-3
5.1.10. 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:
5.1.10.1. Manual Method
When a tape jam is encountered, check the tape loading condition and use the following procedure to
remove a tape jam.
Fig. 8-1
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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. 8-2
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. 8-3
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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.
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.)
5.1.10.2. 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 cut the Motor Leads with
a cutter, etc.
Otherwise, the Loading Motor Drive IC (IC2501) may be damaged.
When reconnecting the Motor Leads, solder at below / 320 °C for less
than 3 seconds.
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 cut the Motor Leads with a cutter, etc.
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.
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