Omnivision PVQ-130W User manual

ORDER NO. MKE0008107C1
B6
Combination VCR
PVQ-130W
PVQ-130WA
PVQ-1300W
PVQ-1300WA
SPECIFICATIONS
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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 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 VCR whose chassis is not isolated from the AC power line. Use a
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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
1 kΩ
ΩΩ
Ω(Cold chassis ground)
24 V
180Ω
ΩΩ
Ω(Cold chassis ground)
15 V
110Ω
ΩΩ
Ω(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 MΩ
ΩΩ
Ωand 12 MΩ
ΩΩ
Ω. When the exposed metal does not
have a return path to the chassis, the reading must be infinity.
LEAKAGE CURRENT HOT CHECK
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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
ΩΩ
Ω, 10 W resistor, in parallel with a 0.15µ
µµ
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
ΩΩ
Ω/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 customer.
Figure 1
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
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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
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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.
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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.
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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
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Fig. 1-3
Fig. 1-4
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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
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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
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5.1.2.1.2. Service Position (2)
Fig. 2-2
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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
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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.
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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
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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.)
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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"
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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
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