Hitachi vt-p298gk Service Manual
SERVICE MANUAL
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TK No. 5303E
VT-P298GK
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VIDEO CASSETTE DECK
June 2003
Digital Media Division, Tokai
NTSCPAL
CONTENTS
1 CAUTIONS FOR SAFETY IN PERFORMING
REPAIR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-1
1-1 IMPORTANT SAFETY PRECAUTIONS . . . . . . . . . 1-1
1-1-1 Product Safety Notice . . . . . . . . . . . . . . . . . . . . . 1-1
1-1-2 Precautions during Servicing. . . . . . . . . . . . . . . . 1-1
1-1-3 Safety Check after Servicing. . . . . . . . . . . . . . . . 1-2
1-2 STANDARD NOTES FOR SERVICING. . . . . . . . . . 1-3
1-2-1 Circuit Board Indications . . . . . . . . . . . . . . . . . . . 1-3
1-2-2 Instructions for Connectors . . . . . . . . . . . . . . . . . 1-3
1-2-3 How to Remove/Install Flat Pack-IC . . . . . . . . . . 1-3
1-2-4 Instructions for Handling Semi-conductors . . . . . 1-5
1-3 NOTES WHEN USING SERVICE MANUAL . . . . . . 1-6
2 GENERAL INFORMATION. . . . . . . . . . . . . . . . .2-1
2-1 SPECIFICATIONS. . . . . . . . . . . . . . . . . . . . . . . . . . 2-1
2-2 FEATURES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1
2-3 COMPARISON OF MODELS . . . . . . . . . . . . . . . . . 2-2
2-3-1 Comparison of Features . . . . . . . . . . . . . . . . . . . 2-2
2-3-2 Comparison of Main Control ICs. . . . . . . . . . . . . 2-3
2-4 MECHANICAL TROUBLE INDICATOR. . . . . . . . . . 2-4
2-5 OPERATING CONTROLS AND FUNCTIONS . . . . 2-5
3 MAINTENANCE AND INSPECTION. . . . . . . . . .3-1
3-1 TROUBLESHOOTING. . . . . . . . . . . . . . . . . . . . . . . 3-1
3-2 STANDARD MAINTENANCE . . . . . . . . . . . . . . . . . 3-4
3-2-1 Service Schedule of Components. . . . . . . . . . . . 3-4
3-2-2 Cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-5
4 DISASSEMBLY. . . . . . . . . . . . . . . . . . . . . . . . . .4-1
4-1 CABINET DISASSEMBLY INSTRUCTIONS. . . . . . 4-1
4-1-1 Disassembly Flowchart . . . . . . . . . . . . . . . . . . . . 4-1
4-1-2 Disassembly Method. . . . . . . . . . . . . . . . . . . . . . 4-1
4-2 DISASSEMBLY/ASSEMBLY PROCEDURES
OF DECK MECHANISM . . . . . . . . . . . . . . . . . . . . . 4-4
4-3 ALIGNMENT PROCEDURES OF MECHANISM. . 4-12
6 EXPLODEDS VIEWS AND PARTS LIST . . . . . 6-1
6-1 EXPLODED VIEWS . . . . . . . . . . . . . . . . . . . . . . . . .6-1
6-1-1 Cabinet Section. . . . . . . . . . . . . . . . . . . . . . . . . . .6-1
6-1-2 Deck Mechanism View 1 Section . . . . . . . . . . . . .6-2
6-1-3 Deck Mechanism View 2 Section . . . . . . . . . . . . .6-3
6-1-4 Deck Mechanism View 3 Section . . . . . . . . . . . . .6-4
6-2 REPLACEMENT PARTS LIST . . . . . . . . . . . . . . . . .6-5
6-2-1 Mechanical Parts List . . . . . . . . . . . . . . . . . . . . . .6-5
6-2-2 Electrical Parts List . . . . . . . . . . . . . . . . . . . . . . . .6-6
SCHEMATIC, CIRCUIT BOARD AND BLOCK
DIAGRAMS
1 WIRING DIAGRAMS. . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
2 SCHEMATIC DIAGRAMS. . . . . . . . . . . . . . . . . . . . . . . . 2
2-1 Main 1/4 Sche matic Diagram. . . . . . . . . . . . . . . . . . . . 2
2-2 Main 2/4 & Sensor & Switc h Schematic Diagrams . . . 3
2-3 Main 3/4 Sche matic Diagram. . . . . . . . . . . . . . . . . . . . 4
2-4 Main 4/4 Sche matic Diagram. . . . . . . . . . . . . . . . . . . . 5
2-5 Function Schematic Diagram. . . . . . . . . . . . . . . . . . . . 6
3 WAVEFORMS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
4 CIRCUIT BOARD DIAGRAMS . . . . . . . . . . . . . . . . . . . . 8
4-1 Main CBA & Sensor CBA Top View. . . . . . . . . . . . . . . 8
4-2 Main CBA Bottom View. . . . . . . . . . . . . . . . . . . . . . . . 9
4-3 Function & Switch CBA Top / Bottom View . . . . . . . . 10
5 BLOCK DIAGRAMS . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
5-1 Servo/System Control Block Diagram. . . . . . . . . . . . 11
5-2 Video Block Diagram. . . . . . . . . . . . . . . . . . . . . . . . . 12
5-3 Audio Block Diagram. . . . . . . . . . . . . . . . . . . . . . . . . 13
5-4 Power Supply Block Diagram . . . . . . . . . . . . . . . . . . 14
6 SYSTEM CONTROL TIMING CHARTS . . . . . . . . . . . . 15
7 IC PIN FUNCTION DESCRIPTIONS . . . . . . . . . . . . . . 18
8 LEAD IDENTIFICATIONS. . . . . . . . . . . . . . . . . . . . . . . 20
5 ADJUSTMENT . . . . . . . . . . . . . . . . . . . . . . . . . .5-1
5-1 PREPARATION FOR SERVICING . . . . . . . . . . . . . 5-1
5-1-1 How to Enter the Service Mode. . . . . . . . . . . . . . 5-1
5-2 FIXTURE AND TAPE FOR ADJUSTMENT. . . . . . . 5-2
5-2-1 How to Use The Fixtures. . . . . . . . . . . . . . . . . . . 5-2
5-3 ELECTRICAL ADJUSTMENT INSTRUCTIONS . . . 5-3
5-3-1 Test Equipment Required . . . . . . . . . . . . . . . . . . 5-3
5-3-2 Head Switching Position Adjustment. . . . . . . . . . 5-3
5-4 MECHANICAL ALIGNMENT PROCEDURES. . . . . 5-4
5-4-1 Service Information . . . . . . . . . . . . . . . . . . . . . . . 5-4
5-4-2 Tape Interchangeability Alignment . . . . . . . . . . . 5-5
1-A. Preliminary/Final Checking and
Alignment of Tape Path. . . . . . . . . . . . . . . . . . . . 5-6
1-B. X Value Alignment. . . . . . . . . . . . . . . . . . . . . . . . 5-6
1-C. Checking/Adjustment of Envelope Waveform. . . 5-7
1-D. Azimuth Alignment of
Audio/Control/Erase Head. . . . . . . . . . . . . . . . . . 5-7
1
CAUTIONS FOR SAFETY IN PERFORMING REPAIR
1-1 IMPORTANT SAFETY PRECAUTIONS
1-1-1 Product Safety Notice
Some electrical and mechanical parts have special
safety-related charac teristics which are often not evident from visual inspection, nor can the protection they
give necessarily be obtained by replacing them with
components rated for higher voltage, wattage, etc.
Parts that have special s afe ty c har ac te rist ic s ar e i den tified by a ! on schematics and in parts lists. Use of a
substitute replacement that does not have the same
safety characteristics as the recommended replacement part might create shock, fi re, and/or other hazards. The Product’s Safety is under review
continuously and new instructions are issued whenever appropriate. Prior to shipment from the factory,
our products are carefully inspected to confirm with
the recognized prod uct safety and electrical codes of
the countries in whic h th ey are to be sold. However, in
order to maintain such comp lianc e, it is equ ally impor tant to implement the following precautions when a set
is being serviced.
1-1-2 Precautions during Servicing
A. Parts identified by the ! symbol are critical for
safety. Replace only with part number specified.
B. In addition to safety, other parts and assemblies
are specified for conformance with regulations
applying to spur ious rad iation. T hese m ust also be
replaced only with specified re pla ce men ts.
Examples: RF converters, RF c ables, noise blocking capacitors, and noise blocking filters, etc.
C. Use specified internal wiri ng. Note especially:
1)Wires covered with PVC tubing
2)Double insulated wires
3)High voltage leads
D. Use specified insulating materials for hazardous
live parts. Note especially:
1)Insulation tape
2)PVC tubing
3)Spacers
4)Insulators for transistors
E. When replacing AC primary side components
(transformers, power cord, etc.), wrap ends of
wires securely about the terminals before soldering.
F. Observe t hat the wi r es do n ot co ntact h eat pr od uc-
ing parts (heatsinks, oxide metal fil m re sisto rs, fus ible resistors, etc.).
G. Check that replaced wires do not contact sharp
edges or pointed parts.
H. When a power cord has been r eplaced, c heck that
5 - 6 kg of force in any direction will not loosen it.
I. Also check areas surrounding repaired locations.
J. Be careful that foreign objects (screws, solder
droplets, etc.) do not remain inside the set.
K. Crimp type wire connector
The power tr ansformer uses crimp type connectors
which connect the power cord and the primary side
of the transformer. When replacing the transformer,
follow these steps carefully and precisely to prevent
shock hazards.
Replacement procedure
1)Remove the old connector by cutting the wires at a
point close to the connector.
Important: Do not re-use a connector. (Discard it.)
2)Strip about 15 mm of the insulation from the ends
of the wires. If the wires are stranded, twist the
strands to avoid frayed conductors.
3)Align the lengths of the wires to be connected.
Insert the wires fully into the connector.
4)Use a crimping tool to crimp the metal sleeve at its
center. Be sure to crimp fully to th e complete closure of the tool.
L. When connecting or disconnecting the internal
connectors, first, discon nect the AC plug from the
AC outlet.
1-1
e)
Z
r
1-1-3 Safety Check after Ser vicing
Examine the area surrounding the repaired location for
damage or deterio ration. Observe that screws , parts,
and wires have been returned to their original positions. Afterwards, do the following tests and confirm
the specified values to verify compliance with safety
standards.
1. Clearance Distance
When replacing primary circuit components, confirm
specified cleara nce distanc e (d) and (d’) between sol dered terminals, and between terminals and surrounding metallic parts. (See Fig. 1-1-1)
T able 1-1-1 : Ratings for selected area
AC Line Voltage Clearance Distance (d) (d’)
Chassis or Secondary Conducto
Primary Circuit Terminals
dd'
110 to 240 V
Note: This table is unofficial and for reference only.
Be sure to confirm the precise values.
≥ 3 mm(d)
≥ 6 mm(d’)
2. Leakage Current Test
Confirm the specified (or lower) leakage current
between B (earth ground, power cord plug prongs)
and externally exposed accessible parts (RF terminals, antenna terminals, video and audio input and
output terminals, microphone jacks, earphone jacks,
etc.) is lower than or equal to the specified value in the
table below.
Measuring Method (Power ON) :
Insert load Z between B (earth ground, power cord
plug prongs) and exposed accessible parts. Use an
AC voltmeter to measure acr oss the ter minals of l oad
Z. See Fig. 1-1-2 and the following table.
Table 1-1-2: Leakage current ratings for selected areas
AC Line Voltage Load Z Leakage Current (i)
110 to 240 V
2kΩ RES.
Connected in parallel
50kΩ RES.
Connected in parallel
i≤0.7mA AC Peak
i≤2mA DC
i≤0.7mA AC Peak
i≤2mA DC
Exposed Accessible Part
One side of
B
Power Cord Plug Prongs
One side of power cord plug
Antenna terminals
A/V Input, Output
Fig. 1-1-1
AC Voltmeter
(High Impedanc
Fig. 1-1-2
prongs (B) to:
RF or
Note: This table is unofficial and for reference only. Be sure to confirm the precise values.
1-2
1-2 STANDARD NOTES FOR SERVICING
O
P
P
1-2-1 Circuit Board Indications
1. The output pin of the 3 pin Regulator ICs is indicated as shown.
Top View
Input
ut
2. For other ICs, pin 1 and every fifth pin are indicated
as shown.
In
in 1
3. The 1st pin of every male connector is indicat ed as
shown.
in 1
Bottom View
5
10
1-2-3 How to Remove / Install Flat
Pack-IC
1. Removal
With Hot-Air Flat Pack-IC Desoldering Machine:.
(1) Prepare the hot-air flat pack-IC desoldering
machine, then apply hot air to the Flat Pack-IC
(about 5 to 6 seconds). (Fig. 1-2-1)
Fig. 1-2-1
(2) Remove the flat pack-IC with tweezers while apply-
ing the hot air.
(3) B ottom of the flat pack-IC is fixed with glue to the
CBA; when removing entire fl at pack-IC, fir st apply
soldering iron to center of the fla t pack-IC and hea t
up. Then remove (glue will be melted). (Fig. 1-2-6)
(4) R elease the flat pack -IC from the CBA usi ng twee-
zers. (Fig. 1-2-6)
1-2-2 Instructions for Connectors
1. When you connec t o r dis con nect the F FC (Flex ib le
Foil Connector) cable, be sure to first disconnect
the AC cord.
2. FFC (Flexible Foil Connector) cable should be
inserted parallel into the connector, not at an angle.
FFC Cable
Connector
CBA
* Be careful to avoid a short circuit.
Caution:
1. Do not supply hot air to the chip parts around the
flat pack-IC for over 6 seconds because damage to
the chip parts may occur. Put maskin g tape a r ound
the flat pack-IC to protect other parts from damage.
(Fig. 1-2-2)
2. The flat pack-IC on th e CB A i s affixed with glue, so
be careful not to break or damage the foil of each
pin or the solder lands under the IC when removing
it.
Hot-air
Flat Pack-IC
Desoldering
CBA
Masking
Tape
Tweezers
Machine
Flat Pack-IC
Fig. 1-2-2
1-3
With Soldering Iron:
F
F
S
rp
or
n
(1)Using desoldering braid, remove the solder from all
pins of the flat pack-IC. Wh en you use solder flux
which is applied to all pins of the f lat pack-IC, you
can remove it easily. (Fig. 1-2-3)
lat Pack-IC
Desoldering Braid
(4) B ottom of the flat pack-IC is fixed with glue to the
CBA; when removing entire fl at pack-IC, fir st apply
soldering iron to center of the fla t pack-IC and hea t
up. Then remove (glue will be melted). (Fig. 1-2-6)
(5) R elease the flat pack -IC from the CBA usi ng twee-
zers. (Fig. 1-2-6)
Note:
When using a sold ering iron, care must be taken
to ensure that the flat pack-IC is not being hel d by
glue. When the flat pack-IC is removed from the
CBA, handle it ge ntl y bec au se it may be damaged
if force is applied.
Soldering Iron
Hot Air Blower
Fig. 1-2-3
(2) Lift each lead of the flat pack-IC upward one by
one, using a sharp pin or wire to which sold er will
not adhere (iron wir e). When heati ng the pins, us e
a fine tip soldering iron or a hot air desoldering
machine. (Fig. 1-2-4)
Iron Wire
Soldering Iron
To Solid
Mounting Point
Sha
Fig. 1-2-5
Pin
ine Tip
oldering Iron
CBA
Fine Tip
Soldering Iro
Fig. 1-2-4
(3)Botto m of the flat pack-IC is fixed with glue t o the
CBA; when removing enti re flat pack-IC, fi rst apply
soldering iron to c en ter o f th e f lat pack-I C an d h eat
up. Then remove (glue will be melted). (Fig. 1-2-6)
(4)Relea se the flat pack-IC fr om the CBA usin g twee-
zers. (Fig. 1-2-6)
Tweezers
Flat Pack-IC
With Iron Wire:
(1)Using desoldering braid, remove the solder from all
Fig. 1-2-6
pins of the flat pack-IC. Wh en you use solder flux
which is applied to all pins of the f lat pack-IC, you
can remove it easily. (Fig. 1-2-3)
(2) Affix the wire to a workbench or solid mounting
point, as shown in Fig. 1-2-5.
(3) While heating the pins using a fine tip soldering
iron or hot air blower, pull up the wire as the solde r
melts so as to lift the IC leads from the CBA contact
pads as shown in Fig. 1-2-5.
1-4
2. Installation
P
i
d
(1) Using desoldering braid, remove the solder from
the foil of each pin of the flat pack-IC on the CBA
so you can install a replac ement flat pack-IC more
easily.
(2) The “I” mark on the flat pack-IC indicates pin 1.
(See Fig. 1-2-7.) Be sure this m ark matches the 1
on the PCB when position ing for installation. Then
presolder the four corners of the flat pack-IC. (S ee
Fig. 1-2-8.)
(3)Solder all pins of the flat pack-IC. Be sure that none
of the pins have solder bridges.
Example :
in 1 of the Flat Pack-IC
s indicated by a " " mark.
Fig. 1-2-7
1-2-4 Instructions for Handling
Semi-conductors
Electrostatic breakdown of the semi-conductors may
occur due to a po tential difference ca used by electr ostatic charge during unpacking or repair work.
1. Ground for Human Body
Be sure to wear a gr oundin g band (1MΩ) that is properly grounded to re move any static electricity th at m ay
be charged on the body.
2. Ground for Workbench
(1) Be sure to place a conductive sheet or copper plate
with proper groundin g (1MΩ) on the workbench or
other surface, where the semi-conductors are to be
placed. Because the static electricity charge on
clothing will no t escape through the body grounding band, be careful to avoid contacting semi-conductors with your clothing.
< Incorrect >
CBA
Presolder
Flat Pack-IC
Fig. 1-2-8
CBA
< Correct >
Grounding Ban
1MΩ
CBA
1MΩ
Conductive Sheet or
Copper Plate
1-5
1-3 NOTES WHEN USING SERVICE MANUAL
(
l
The following shows the contents to be noted when using service manual:
Standard Notes
WARNING
Many electrical and mechanical parts in this chassis
have special characteristics. These characteristics
often pass unnoticed and the protection afforded by
them cannot nece ssar ily b e ob tai ned by us ing repl ac ement components rated for higher voltage, wattage,
Notes:
1. Do not use th e part numb er shown o n these drawings for ordering. The correct part number is shown
in the parts list, and may be slightly different or
amended since these drawings were prepared.
2. All voltages are DC voltages unless otherwise
specified.
etc. Replacement parts that have th ese spe cial safety
characteristics are identified in this manual and its
supplements; electrical comp onents having such features are identified by the mark " ! " in the schematic
diagram and the parts list. Before replacing any of
these components, read the parts list in this manual
carefully. The use of substitute replacement parts that
Values in schematic diagrams
The values, dielectric strength (power capacitance)
and tolerances of the resistors (excluding variable
resistors) and capacitors are indicated in the sche-
matic diagrams using abbreviations.
do not have the same s afety character istics as specified in the parts list may create shock, fire, or other
hazards.
Capacitor Temperature Markings
Mark
(B)
Capacity
change rate
±10%
(F) +30 - 80% 20°C -25~+85°C
(SR)
±15%
Standard
Temperature
temperature
20°C -25~+85°C
20°C -25~+85°C
range
[ Resistors ]
Item Indication
No indication.............................Ω
Value
K..............................................kΩ
M.............................................MΩ
No indication...............1/4W,1/6W
Power capac-
itance
All capacitances other than the
above are indicated in schematic
diagrams.
(Z) +30 - 80% 20°C -10~+70°C
[ Capacitors ]
Capacitors and transistor s are represented by the following symbols.
CBA Symbols
(Top View) (Bottom View)
Bottom View)
E C B
(Top View)
E C B
(Top View)
E C B
+
Electrolytic Capacitor
Transistor or Digital Transistor
(Top View)
NPN
Transistor
NPN Digital
Transistor
E C B
(Top View)
E C B
PNP
Transistor
PNP Digita
Transistor
Item Indication
Value
No indication...........................µF
P..............................................pF
No indication..........................50V
Dielectric
strength
All dielectric strengths other than
50V are indicated in schematic
diagrams.
[ Coils ]
Item Indication
Value
µ...............................................µH
m.............................................mH
1-6
Schematic Diagram Symbols
Digital Transistor
LIST OF CAUTION, NOTES, AND SYMBOLS USED IN THE SCHEMATIC DIAGRAMS ON THE FOLLOWING
T
b
m
ts
1
".
".
3
2
1
PAGES:
1. CAUTION:
FOR CONTINUED PROTECTION AGAINST FIRE HAZARD, REPLACE ONLY WITH THE SAME TYPE FUSE.
2. CAUTION:
Fixed Voltage (or Auto voltage selectable) power supply circuit is used in this unit.
If Main Fuse (F1001) is blown, first check to see that all components in the power supply circuit are not defective
before you connect the AC plug to the AC power supp ly. Otherwi se it may cause some compon ents in the
power supply circuit to fail.
3. Note:
(1) Do not use the part number shown on the drawings for ordering. The correct part number is shown in the parts
list, and may be slightly different or amended since the drawings were prepared.
(2) To maintain original function and reliability of repaired units, use only original replacement parts which are
listed with their part numbers in the parts list section of the service manual.
4. Wire Connectors
(1) Prefix symbol "CN" means "connector" (can disconnect and reconnect).
(2) Prefix symbol "CL" means "wire-solder holes of the PCB" (wire is soldered directly).
5. Voltage indications for PLAY and REC modes on the schematics are as shown below:
he same voltage for
oth PLAY & REC
odes
6. How to read converged lines
-D3
Distinction Area
Line Number
(1 to 3 digits)
Examples:
1. "1-D3" means that line number "1" goes to area "D3
2. "1-B1" means that line number "1" goes to area "B1
7. Test Point Information
: Indicates a test point with a jumper wire across a hole in the PCB.
: Used to indicate a test point with a component lead on foil side.
: Used to indicate a test point with no test pin.
123
5.0
5.0
(2.5)
Indicates that the voltage
is not consistent here.
PLAY mode
Unit: Vol
REC mode
1-B1
AREA D3
AREA B1
1-D3
ABCD
: Used to indicate a test point with a test pin.
1-7
GENERAL INFORMATION2
•
•
•
•
•
•
•
•
e
.
-
he
is
V,
h
ay
3
hours of playback with a T-160 tape.
P
T
T
L
U
R
H
A
V
R
m
without notice.
2-1 SPECIFICATIONS
GENERAL SPECIFICATIONS
layback system: Twin heads,
Helical scanning system
ape width: 12.7mm (1/2 inch)
ape speed SP: 23.39mm/s
P: 11.70mm/s
sable tape: VHS video cassette
F output: UHF channel 22 to 69 for
PAL G/K
orizontal resolution: 230 TV lines
for VHS Terminals
udio input/output: RCA connector ✕2
ideo input/output: RCA connector ✕ 2
F input/output: IEC connector ✕2
ELECTRICAL SPECIFICATIONS
Video input: 0.5~2.0Vp-p
Video output: 1Vp-p75 ohm unbalanced
Video S/N: 42dB
Audio input: -10dBV
Audio output: -6dB
Audio frequency response: 200Hz to 6 kHz
Audio S/N: 40dB
OTHER SPECIFICATIONS
Power consumption: 12W
Operation temperature:
Main input: 110-240V, 50/60Hz
Cabinet dimension:
Weight: Approx. 2.0kg
Accessories: RF cord/ Remote control
Design and specifications are subject to change
5 C to 40 C
360(W) ✕ 92(H) ✕216(D) m
AV cable
2-2 FEATURES
Auto Power On and Stand-by System–
Automatically turns the VCP on as you insert a tape.
When the end of a tape is reached, the VCP will automatically rewind to the beginning. The tape will be
ejected and the VCP will shut itself off.
Auto Play– When you insert a tape without the erase
prevention tab, the VCP starts playback automatically.
Auto Rewinding– When the end of a tape is reached
during playback or fast-forward, the VCP will automatically rewind to the beginning.
Auto Eject– The cassette mechanism will disengage
after rewinding and the tape will be ejected and the
VCP will shut itself off.
Repeat Playback– Allows you to repeat a tape indefinitely without pressing the PLAY button.
Auto Tracking– Adjusts the tracking automatically
for each tape you play.
Auto Head Cleaner– Automatically cleans heads as
you insert or remove a cassette.
Picture Control– Improves playback picture quality
of worn tapes, especially rental tapes.
• Speed Search– You may view the video programm
at a fast speed in either forward or reverse direction
• Line Recording– You can record a programme from
another source via the AUDIO/VIDEO IN sockets.
• Multi color System– PALor MESECAM recorded
tapes can be played back with a multi system receiv
er.
• NTSC Playback– Tapes recorded with the NTSC
system can be played back with this unit via a PAL
system TV set. (This feature is only available in the
SP mode).
• Infrared Remote Control– Allows you to use all t
tape transport controls and STANDBY on/off from
remote location.
• Auto Voltage (AC110-240V, 50/60Hz)– This VCP
designed to match the AC power voltage 110V-240
50/60Hz automaticcaly.
• 2 Step Picture Search Operation– Allows you to
view the video program at a high speed or super hig
speed in either a forward or reverse direction in the
LP mode.
• Two different tape speeds– Select the Standard Pl
(SP mode) and Long Play (LP mode) for up to 5-1/
2-1
2-3 COMPARISON OF MODELS
2-3-1 Comparison of Features ←: Same as on left
ITEM VT-P298GK VT-P198GK/P198GK(U)/(G)
Cabinet Dimension 360(W) x 92(H) x 216(D) mm
Weight 2.0kg
Power Consumption 12W 14W
APPEARANCE
Video Format VHS
Y/C Separation Comb Filter
YNR (Luminance Noise Reduction)
Circuit
VIDEO
New Synchronise Circuit Not Provided
Picture Control Provided (NORMAL/SOFT/SHARP)
Video/Audio Input (Rear) 1/1 (Line Rec)
Video/Audio Input (Front) Not Provided
INPUT/
Video/Audio Output (Rear) 1/1
OUTPUT
Remote Controller VT-RMP298GK VT-RMP98GK/VT-RMP99GK
OSD Ianguages 1(English)
Stereo CM Skip Feature Not Provided
Auto Clock Feature Not Provided
Number of Timer Programming Not Provided
Self Diagnosis Function Provided (5 Modes)
Back-up Time Not Provided
OTHERMECHANISM
SQPB Not Provided
NTSC playback on PAL TV Provided
Surge Absorber Not Provided
Auto Power Off Feature Provided (AUTO REW P-OFF)
Local Broadcast Setting Not Provided
Multi Search Feature Not Provided
Search Speed
FF/REW Time (T-120 Tape) FF/REW: approx. 4min
Head Composition 32 µm/32 µm
Head Material Ferrite
VISS Not Provided
PAL SP:X5/X7, LP:X5/X11,
Provided
NTSC SP:X5
←
←
←
←
←
←
←
←
←
←
←
←
←
←
←
←
←
←
←
←
←
←
←
←
←
←
←
2-2
2-3-2 Comparison of Main Control ICs ←: Same as on left
ITEM OPERATION VT-P298GK VT-P198GK/P198GK(U)/(G)
Video Video Signal Process LA71584M (IC301)
Audio
System Control
Timer Display Driver Included in IC501
Power Switching Driver Not Provided
FM Audio Signal Process Not Provided
Linear Audio Signal Process Included in IC301
Main Microcomputer µP M37762MCA-AB2GP (IC501) M37768M6A-1D6GP (IC501)
VCR-EEP ROM BR24C01AF-W (IC503)
Reset Not Provided
Loading Motor Drive
Cylinder/Loading Motor
Control
Power Reset
Included in IC on the Capstan Motor
CBA
Included in IC on the Capstan Motor
CBA
Included in IC on the Capstan Motor
CBA
M24C01-MN6 (IC505)
←
←
←
←
←
←
←
←
←
2-3
2-4 MECHANICAL TROUBLE INDICATOR
Note:
The following symbols will appear on the indicator panel to indicate mechanical trouble.Display panel.
Indicator Mode
at 0.4Hz interval When power safety is not functioning properly.
at 0.8Hz interval When capstan/reel mechanism is not functioning properly.
REPEAT
at 1.6Hz interval When tape loading mechanism is not functioning properly.
at 3.2Hz interval When cassette loading mechanism is not functioning properly.
at 6.4Hz interval When the drum is not functioning properly.
2-4
– FRONT VIEW –
PLAY
REW
REC
REC
F.FWD
STOP/EJECT
REPEAT
REPEAT
SYSTEM
SELECT
OPERATE
STANDBY ON
678911
12435
10
AUDIO
VIDEO
RF OUT
AERIAL
OUT IN
1312 14 1715 16
1
1
1
2-5 OPERATING CONTROLS AND FUNCTIONS
1 CASSETTE COMPARTMENT
2 REW (VISUAL SEARCH) button– Press to
rewind tape or to view video in reverse during
playback at a fast speed. Press the PLAY button to
return to normal speed.
3 PLAY button– Press to begin playback of a tape.
4 F. FWD (VISUAL SEARCH) button– Press to
advance tape or to view video in forward direction
during playback at a fast speed. Press the PLAY
button to return to normal speed.
5 STOP/EJECT button– Press to stop tape motion /
remove tape from the appliance.
6 REPEAT button– Press to repeat playback
automatically.
7 REC button– Press to record a broadcast from
another source.
– REAR VIEW AND TERMINALS –
8 SYSTEM SELECT button– Press to select the
colour system PAL, MESECAM, NTSC 4.43 or
NTSC3.58. (See “PLAYBACK” section.)
9 INDICATOR
• STANDBY– Lights on when power is connected.
• ON– Lights on when the VCP turns on.
• REPEAT– Lights on when the Repeat Playback is
functioned.
• REC– Lights on during recording.
10 Remote Sensor window– Receives the infrared
control signals from the remote control unit.
11 OPERATE button– Press to turn the VCP on and
stand-by.
2 AUDIO OUTjack– Connect to the audio input
jack of your TV.
3 VIDEO OUT jack– Connect to the video input
jack of your TV.
4 VIDEO IN jack– Connect to video output jack of
your video equipment.
15 AUDIO IN jack– Connect to audio output jack of
your audio equipment.
16 RF OUT jack– Connect to aerial jack of your TV.
17 AERIALjack– Connect to the TV aerial coaxial
cable.
2-5
You can operate most of your VCP’s tape transport functions from the Remote Control (supplied).
T
he buttons on the Remote Control have the same functions as the corresponding buttons on the VCP.
H
1
1
1
er
0:12:34 SP
0:12:34
<OFF mode>
<COUNTER mode>
Press once
Press once
5 seconds
<STATUS mode>
OPERATE
REW
PLAY
STOP
F.FWD
PAUSE/STILL
REPEAT
DISPLAY
REC
SPEED
EJECT
PICTURE
SELECT
RESET
COUNTER
MEMORY
TRACKING
2
6
7
5
3
4
1
8
9
10
11
13
15
14
12
OW TO USE THE REMOTE CONTROL
1 OPERATE button– Press to turn the VCP on and
stand-by.
2 TRACKING buttons– Press to adjust to minimize
video “noise” (lines or dots on screen) during
playback. Most often, this is necessary when
playing pre-recorded tapes or tapes recorded on
other VCP’s.
3 DISPLAY button– Press to
display the tape status, TV screen.
Each time you press this button,
TV screen will change as shown.
4 REPEAT button– Press to repeat
playback automatically.
5 PLAY button– Press to begin
playback of the tape.
6 REW (VISUAL SEARCH)
button– Press to rewind the tape.
Or press to view the picture rapidly in reverse,
during the Playback mode.
7 REC button– Press to begin recording.
8 SPEED button– Press to set desired recording
speed (SP/LP).
9 PAUSE/STILL button– Press to stop the tape
temporarily during playback or recording.
0 STOPbutton– Press to stop tape motion.
1 F.FWD (VISUAL SEARCH) button– Press to
move the tape forward rapidly. Or press to view the
picture rapidly in forward during the Playback
mode.
2 PICTURE SELECT button– Press to improve the
playback picture quality of noisy tapes. (ex: rental
tape etc.)
13 COUNTER RESET button– Press to reset count
to 0:00:00.
14 COUNTER MEMORYbutton– Press to set
counter memory on and off.
15 EJECT button– Press to remove tape from the
VCP.
2-6
MAINTENANCE AND INSPECTION3
3-1 TROUBLESHOOTING
Troubleshooting is how to service for the specifying malfunction or poor parts.
Detect malfunction or poor parts and service as the following charts.
Video problem 1 (No recording Video)
LINE INPUT (AV)
Check Video signal at pin (38) of IC301. Check AV cable, JK752 and line between JK752 and
OK
Check Video signal at pins (31, 51, 72) of IC301.
OK
Check Video signal at pin (20) of IC301.
OK
Check Video signal at pin (90) of IC301.
OK
Cleaning the Video Head. (See page 3-5.) Or check Cylinder Assembly and service it if defective.
NG
NG
NG
NG
pin (38) of IC301, and service it if defective.
Check IC301, X301, etc., and service it if defective.
Check Q304 and their periphery, and service it if
defective.
Check IC301, X301, etc., and service it if defective.
Video problem 2 (No playback Video)
Check Video signal at pins (88, 90) of IC301 and TP301 (C-PB).
OK
Check Video signal at
pins (51, 72) of IC301.
OK
Check Video signal at pin (20) of IC301.
OK
Check Video signal at pin (29) of IC301.
NG
Check IC301, X301, etc.,
and service it if defective.
NG
NG
Cleaning the Video Head. (See page 3-5.) Or check
Cylinder Assembly and service it if defective.
Check Q304 and their periphery, and service it if
defective.
Check IC301, X301, etc., and service it if defective.
NG
OK
Check Video signal at pin (52) of IC501.
OK
RF OUT LINE OUT
Check Video signal at pin (6) of MD701.
OK OK
Check MD701 and service it if defective.
Check line between pin (52) of IC501 and pin (6) of
MD701, and service it if defective.
NG
NG NG
Check IC501, X501 and line between pin (29) of IC301
and pin (50) of IC501, and service it if defective.
Check Video signal at pin (19) of JK751.
Check JK751 and AV cable, and service it if
defective.
Check line between pin (52) of IC501 and JK751, and
service it if defective.
3-1
Audio problem 1 (No recording Normal Audio)
LINE INPUT (AV)
Check Audio signal at pin (76) of IC301.
OK
Check Audio signal at pins (7, 96) of IC301.
OK
Check Tape interchangeability alignment.
(See page 3-5.)
NG
Cleaning the Audio Control Head. (See page 3-5.)
NG
NG
NG
Audio problem 2 (No playback Normal Audio)
(AV)
Check Audio signal at pin (4) of IC301.
OK
NG
Check AV cable, JK752 and line between JK752 and
pin (76) of IC301, and service it if defective.
Check IC301, X301, etc., and service it if defective.
Check ACE Head Assembly and service it if defective.
Check Tape interchangeability
alignment. (See page 5-5.)
NG
Check ACE Head Assembly and service
it if defective.
OK
Check Audio signal at pin (96) of IC301.
OK
RF OUT LINE OUT
Check Audio signal at pin (2) of MD701.
OK OK
Check MD701 and service it if defective.
Check line between pin (96) of IC301 and pin (2) of
MD701, and service it if defective.
3-2
Cleaning the Audio Control Head. (See page 3-5.)
NG
NG NG
Check IC301, X301, etc., and service it if defective.
Check
Audio
signal at JK751.
Check JK751 and AV cable, and service it if
defective.
Check line between pin (96) of IC301 and JK751, and
service it if defective.
Power problem
It is highly recommended that a variable isola tion
transformer which can monitor current be used.
(Alternatively a variable AC source which monitors current will do). Read directions below befo re
power is added!
Repair method
CHECK
Connect unit to the isolation transformer and slowly increase the AC supply while monitoring the current, if it
draws too much current (Be ware fuse
is rated for 1.6 amps), then turn off
supply and do repair method #1.
NO
Check whether the primary rectifying
DC of the Switching power supply has
an output. (Reading should be about
168V.)
YES
With the primary DC working check
the secondary 5V.
YES
Are the 12V and 5V higher than
normal?
NO
Although the secondary 5V is working,
are any of the other voltages higher
than normal (12V)?
NO
There is no problem on the SW power
supply.
YES
NO
NO
YES
YES
#1
#2
#3
#4
#5
1] Check for any defect ive parts while the secondary
rectifying diodes are disconnected (D011, D013 and
D014) perform a diode check in both forward and
reverse directions through a tester.
2] Remove the following components and check for
defects: snubber diode ( D00 5) , sw itc hi ng F ET ( Q00 1) ,
source resistor (R006), control transistor (Q002).
Repair method #2
Check the fuse 1.6A (F00 1), primary rectifying d iodes
(D001-D004) as possible problems. Remove the
above mentioned parts and check them. The circuit
which turns on switching FET (Q001) may be
regarded as a possibl e cause, even if the load at the
secondary side is shorted, it can't be detected
because switching FET (Q001) isn't operating. Perform check according to the step 1 and 2 of repair
method #1 and check the following parts:
(Remove the part from PCB)
Switching FET (Q001), source resistor (R006), gate
resistor (R008) and start resistor (R003, R004, R005
and R028).
Repair method #3
A circuit to turn on switching FET (Q001) may not work
and this may be regard ed as a cau se of trouble. Even
if the load at the secondary side is short-circuited, it
cannot be detected because switching FET (Q001)
does not turn on. Therefor e, perform check acco rding
to the steps 1] and 2] of the repair method #1 and execute the under-mentioned parts breakage check.
(Remove the part from PCB.)
switching FET (Q001), source resistor (R006), control
transistor (Q002) , gate resist or (R008) and start resistor (R003, R004, R005 and R028).
Repair method #4
Repair method #1
(Power must be off)
Short circuit in the s econd ary si de. c heck di ode D 011,
D013, D014, switching FET (Q001), control transi stor
(Q002), diode (D006, D018), and resistor (R014)
replace as necessary.
Disconnect 44V diod e (D011), 12V di ode (D013), 5V
diode (D014). Check the load continuity of 44V line,
12V line and 5V line through a tester (resistance
range).
If the tester indic ates a lower resistance v alue around
0 ohm, the line is short-circuited.
Before repairing the switc hing power supply, find out
the short-circuited area of such line and repair it.
If the tester does not indicate any low resistance value
(around 0 ohm), no l oad is shor t-cir cuited a nd the re i s
no problem.
The feedback c ircuit whic h is monitor ed by the output
of voltage may not w ork and this may be regarded as
a possible cause, rem ove control transis tor Q002 and
check for defects. More ov er, a photo coupler (IC001)
and transistor (Q004) may be defective, replace any
defective parts with factory originals.
Repair method #5
If the output voltage of the secondary side is slightly
high, the line load may be in the "OPEN" state and this
may be regarded as a cause of troub le. If there is no
output voltage on the secondary side, the rectifying
diodes (D011) and (D013) may be defective.
3-3
3-2 STANDARD MAINTEN ANCE
3-2-1 Service Schedule of Components
h: Hours : Check I: Change
Deck Periodic Service Schedule
Ref.No. Part Name 1,0 00 h 2,000 h 3,0 00 h 4,000 h
B2
B3 Loading Motor Assembly I
B8
B587
B31 ACE Head Assembly I
B573,B574
B37
B52 Cap Belt II
B73
B133,B134
B410 Pinch Arm(A) Assembly II
B414
B416
Cylinder Assembly
Pulley Assembly
Tension Lever Assembly
Reel (SP)(D2), Reel (TU)(D2)
Capstan Motor
FE Head
Idler Gear, Idler Arm
M Brake (SP) Assembly
M Brake (TU) Assembly
II
II
II
I
II
I
II
II
II
B525 LDG Belt II
B569
Notes:
1.Clean all parts for the tape tr ansport (Upp er Drum with Video Head / Pinch Roll er / Audio Control Head / Full
Erase Head) using 90% lsopropyl Alcohol.
2.After cleaning the parts, do all DECK ADJUSTMENTS.
3.For the reference numbers listed above, refer to Deck Exploded Views.
Cam Holder (F)
II
3-4
3-2-2 Cleaning
V
d
Cleaning of Video Head
Clean the head with a head cleanin g stick or chamois
cloth.
Procedure
1.Remove the top cabinet.
2.Put on a glove (thin type) to avoid touching the
upper and lower drum with your bare hand.
3.Put a few d rops of 90% Isopropyl alcohol o n the
head cleaning stick or on the chamois cloth and,
by slightly pressi ng it a gai ns t th e he ad tip , tur n the
upper drum to the right and to the left.
Notes:
1.The video head surface is made of very hard
material, but since it i s very thin, avoid clea ning it
vertically.
2.Wait for the cleaned part to dry thorough ly before
operating the unit.
3.Do not reuse a stained head cleaning stick or a
stained chamois cloth.
Cleaning of ACE Head
Clean the head with a cotton swab.
Procedure
1.Remove the top cabinet.
2.Dip the cotton swab i n 90% Isopropyl alcoho l and
clean the ACE head. Be careful not to damage the
upper drum and other tape running parts.
Notes:
1.Avoid cleaning the ACE head vertically.
2.Wait for the cleaned part to dry thoroughly before
operating the unit or damage may occur.
ACE Hea
Upper
Cylinder
Do Not !
ideo Head
Cleaning Stick
3-5
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