Citizen CVCR401H User manual

SERVICE MANUAL
Sec. 1: Main Section
ISpecifications
IPreparation for Servicing
IAdjustment Procedures
ISchematic Diagrams
ICBA’s
IExploded Views
IParts List
When servicing the deck
mechanism, refer to MK14 Deck
Mechanism Section.
Deck Mechanism Part No.:
N246UFL
VIDEO CASSETTE RECORDER
CVCR401H
POWER
POWER CHANNEL
VCR/TV TIMERTAPE IN REC
MENUREC/OTRSTOP/EJECT REW PLAY F.FWD
nm
ab
s
PN
V
VIDEO L - AUDIO - R

IMPORTANT SAFETY NOTICE
Proper service and repair is important to the safe, reliable operation of all
Funai Equipment. The service procedures recommended by Funai and
described in this service manual are effective methods of performing
service operations. Some of these service special tools should be used
when and as recommended.
It is important to note that this service manual contains various CAUTIONS
and NOTICES which should be carefully read in order to minimize the risk
of personal injury to service personnel. The possibility exists that improper
service methods may damage the equipment. It also is important to
understand that these CAUTIONS and NOTICES ARE NOT EXHAUSTIVE.
Funai could not possibly know, evaluate and advice the service trade of all
conceivable ways in which service might be done or of the possible
hazardous consequences of each way. Consequently, Funai has not
undertaken any such broad evaluation. Accordingly, a servicer who uses a
service procedure or tool which is not recommended by Funai must first
use all precautions thoroughly so that neither his safety nor the safe
operation of the equipment will be jeopardized by the service method
selected.

MAIN SECTION
VIDEO CASSETTE RECORDER
CVCR401H
TABLE OF CONTENTS
Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-1-1
Important Safety Precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-2-1
Standard Notes for Servicing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-3-1
Preparation for Servicing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-4-1
Cabinet Disassembly Instructions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-5-1
Electrical Adjustment Instructions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-6-1
Function Indicator Symbols. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-7-1
Power Supply Troubleshooting Guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-8-1
Block Diagrams. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-9-1
Schematic Diagrams / CBA's and Test Points. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-10-1
Waveforms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-11-1
Wiring Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-12-1
System Control Timing Charts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-13-1
IC Pin Function Descriptions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-14-1
Lead Identifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-15-1
Exploded Views. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-16-1
Mechanical Parts List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-17-1
Electrical Parts List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-18-1
Sec. 1: Main Section
ISpecifications
IPreparation for Servicing
IAdjustment Procedures
ISchematic Diagrams
ICBA’s
IExploded Views
IParts List

1-1-1 HJ411SP
SPECIFICATIONS
Note: Nominal specs represent the design specs. All units should be able to approximate these – some will
exceed and some may drop slightly below these specs. Limit specs represent the absolute worst condition
that still might be considered acceptable; In no case should a unit fail to meet limit specs.
Description Unit Minimum Nominal Maximum Remark
1. Video
1-1. Video Output (PB) Vp-p 0.8 1.0 1.2 SP Mode
1-2. Video Output (R/P) Vp-p 0.8 1.0 1.2
1-3. Video S/N Y (R/P) dB 40 45 SP Mode,
W/O Burst
1-4. Video Color S/N AM (R/P) dB 35 41 SP Mode
1-5. Video Color S/N PM (R/P) dB 33 36 SP Mode
1-6. Resolution (PB) Line 230 245 SP Mode
2. Servo
2-1. Jitter Low µsec 0.07 0.12 SP Mode
2-2. Wow & Flutter % 0.3 0.5 SP Mode
3. Normal Audio
3-1. Output (PB) dBV -9 -6 -3 SP Mode
3-2. Output (R/P) dBV -9 -6 -1.5 SP Mode
3-3. S/N (R/P) dB 36 41 SP Mode
3-4. Distortion (R/P) % 1.0 4.0 SP Mode
3-5. Freq. resp (R/P) at 200 Hz dB -11 -4 SP Mode
(-20 dB ref. 1 kHz) at 8 kHz dB -14 -4 SP Mode
4. Tuner
4-1. Video output Vp-p 0.8 1.0 1.2 E-E Mode
4-2. Video S/N dB 39 42 E-E Mode
4-3. Audio output dB -10 -6 -2 E-E Mode
4-4. Audio S/N dB 40 46 E-E Mode
5. Hi-Fi Audio
5-1. Output dBV -12 -8 -4 SP Mode
5-2. Dynamic Range dB 70 80 SP Mode
5-3. Freq. resp (6 dB B.W) Hz 20 ~ 20 k SP Mode

1-2-1 VCRN_ISP
IMPORTANT SAFETY PRECAUTIONS
Product Safety Notice
Some electrical and mechanical parts have special
safety-related characteristics 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 safety characteristics are
identified 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, fire, 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 product safety and electrical
codes of the countries in which they are to be sold.
However, in order to maintain such compliance, it is
equally important to implement the following
precautions when a set is being serviced.
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 spurious radiation. These must also be
replaced only with specified replacements.
Examples: RF converters, RF cables, noise
blocking capacitors, and noise blocking filters, etc.
C. Use specified internal wiring. 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 that the wires do not contact heat
producing parts (heat sinks, oxide metal film
resistors, fusible resistors, etc.).
G. Check that replaced wires do not contact sharp
edges or pointed parts.
H. When a power cord has been replaced, check 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 transformer 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 the complete
closure of the tool.
L. When connecting or disconnecting the internal
connectors, first, disconnect the AC plug from the
AC outlet.

1-2-2 VCRN_ISP
Safety Check after Servicing
Examine the area surrounding the repaired location for damage or deterioration. 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 clearance distance (d) and (d’) between
soldered terminals, and between terminals and
surrounding metallic parts. (See Fig. 1)
Table 1: Ratings for selected area
Note: This table is unofficial and for reference only. Be
sure to confirm the precise values.
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 across the terminals of load Z.
See Fig. 2 and the following table.
Table 2: Leakage current ratings for selected areas
Note: This table is unofficial and for reference only. Be sure to confirm the precise values.
AC Line Voltage Clearance Distance (d), (d’)
120 V ≥3.0 mm (0.118 inches)
AC Line Voltage Load Z Leakage Current (i) Earth Ground (B) to:
120 V 0.15 µF CAP. & 1.5 kΩRES.
Connected in parallel i ≤0.5 mA Peak Exposed accessible parts
Chassis or Secondary Conductor
Primary Circuit
Fig. 1
d' d
AC Voltmeter
(High Impedance)
Exposed Accessible Part
BEarth Ground
Power Cord Plug Prongs
Z
Fig. 2

1-3-1 VCRN_SN
STANDARD NOTES FOR SERVICING
Circuit Board Indications
1. The output pin of the 3 pin Regulator ICs is
indicated as shown.
2. For other ICs, pin 1 and every fifth pin are
indicated as shown.
3. The 1st pin of every male connector is indicated as
shown.
Pb (Lead) Free Solder
When soldering, be sure to use the Pb free solder.
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. S-1-1)
2. Remove the flat pack-IC with tweezers while
applying the hot air.
3. Bottom of the flat pack-IC is fixed with glue to the
CBA; when removing entire flat pack-IC, first apply
soldering iron to center of the flat pack-IC and heat
up. Then remove (glue will be melted). (Fig. S-1-6)
4. Release the flat pack-IC from the CBA using
tweezers. (Fig. S-1-6)
CAUTION:
1. The Flat Pack-IC shape may differ by models. Use
an appropriate hot-air flat pack-IC desoldering
machine, whose shape matches that of the Flat
Pack-IC.
2. 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 masking tape
around the flat pack-IC to protect other parts from
damage. (Fig. S-1-2)
3. The flat pack-IC on the CBA is 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.
Top View
Out In
Bottom View
Input
5
10
Pin 1
Pin 1
Fig. S-1-1
Hot-air
Flat Pack-IC
Desoldering
Machine
CBA
Flat Pack-IC
Tweezers
Masking
Tape
Fig. S-1-2

1-3-2 VCRN_SN
With Soldering Iron:
1. Using desoldering braid, remove the solder from
all pins of the flat pack-IC. When you use solder
flux which is applied to all pins of the flat pack-IC,
you can remove it easily. (Fig. S-1-3)
2. Lift each lead of the flat pack-IC upward one by
one, using a sharp pin or wire to which solder will
not adhere (iron wire). When heating the pins, use
a fine tip soldering iron or a hot air desoldering
machine. (Fig. S-1-4)
3. Bottom of the flat pack-IC is fixed with glue to the
CBA; when removing entire flat pack-IC, first apply
soldering iron to center of the flat pack-IC and heat
up. Then remove (glue will be melted). (Fig. S-1-6)
4. Release the flat pack-IC from the CBA using
tweezers. (Fig. S-1-6)
With Iron Wire:
1. Using desoldering braid, remove the solder from
all pins of the flat pack-IC. When you use solder
flux which is applied to all pins of the flat pack-IC,
you can remove it easily. (Fig. S-1-3)
2. Affix the wire to a workbench or solid mounting
point, as shown in Fig. S-1-5.
3. While heating the pins using a fine tip soldering
iron or hot air blower, pull up the wire as the solder
melts so as to lift the IC leads from the CBA
contact pads as shown in Fig. S-1-5.
4. Bottom of the flat pack-IC is fixed with glue to the
CBA; when removing entire flat pack-IC, first apply
soldering iron to center of the flat pack-IC and heat
up. Then remove (glue will be melted). (Fig. S-1-6)
5. Release the flat pack-IC from the CBA using
tweezers. (Fig. S-1-6)
Note: When using a soldering iron, care must be
taken to ensure that the flat pack-IC is not
being held by glue. When the flat pack-IC is
removed from the CBA, handle it gently
because it may be damaged if force is applied.
Flat Pack-IC Desoldering Braid
Soldering Iron
Fig. S-1-3
Fine Tip
Soldering Iron
Sharp
Pin
Fig. S-1-4
To Solid
Mounting Point
Soldering Iron
Iron Wire
or
Hot Air Blower
Fig. S-1-5
Fine Tip
Soldering Iron
CBA
Flat Pack-IC
Tweezers
Fig. S-1-6

1-3-3 VCRN_SN
2. Installation
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 replacement flat pack-IC more
easily.
2. The “●” mark on the flat pack-IC indicates pin 1.
(See Fig. S-1-7.) Be sure this mark matches the 1
on the PCB when positioning for installation. Then
presolder the four corners of the flat pack-IC. (See
Fig. S-1-8.)
3. Solder all pins of the flat pack-IC. Be sure that
none of the pins have solder bridges.
Instructions for Handling Semi-
conductors
Electrostatic breakdown of the semi-conductors may
occur due to a potential difference caused by
electrostatic charge during unpacking or repair work.
1. Ground for Human Body
Be sure to wear a grounding band (1 MΩ) that is
properly grounded to remove any static electricity that
may be charged on the body.
2. Ground for Workbench
Be sure to place a conductive sheet or copper plate
with proper grounding (1 MΩ) on the workbench or
other surface, where the semi-conductors are to be
placed. Because the static electricity charge on
clothing will not escape through the body grounding
band, be careful to avoid contacting semi-conductors
with your clothing.
Example :
Pin 1 of the Flat Pack-IC
is indicated by a " " mark. Fig. S-1-7
Presolder
CBA
Flat Pack-IC
Fig. S-1-8
<Incorrect>
CBA
Grounding Band
Conductive Sheet or
Copper Plate
1MΩ
1MΩ
<Correct>
CBA

1-4-1 HJ420PFS
PREPARATION FOR SERVICING
How to Enter the Service Mode
About Optical Sensors
Caution:
An optical sensor system is used for the Tape Start
and End Sensors on this equipment. Carefully read
and follow the instructions below. Otherwise the unit
may operate erratically.
What to do for preparation
Insert a tape into the Deck Mechanism Assembly and
press the [PLAY] button. The tape will be loaded into
the Deck Mechanism Assembly. Make sure the power
is on, connect TP502 (S-INH) to GND. This will stop
the function of Tape Start Sensor, Tape End Sensor
and Reel Sensors. (If these TPs are connected before
plugging in the unit, the function of the sensors will
stay valid.) See Fig. 1.
Note: Because the Tape End Sensors are inactive,
do not run a tape all the way to the start or the
end of the tape to avoid tape damage.
TP502
S-INH
Q504
Q503
Fig. 1

1-5-1 HJ340DC
CABINET DISASSEMBLY INSTRUCTIONS
1. Disassembly Flowchart
This flowchart indicates the disassembly steps to gain
access to item(s) to be serviced. When reassembling,
follow the steps in reverse order. Bend, route, and
dress the cables as they were originally.
2. Disassembly Method
Note:
(1) Identification (location) No. of parts in the figures
(2) Name of the part
(3) Figure Number for reference
(4) Identification of parts to be removed, unhooked,
unlocked, released, unplugged, unclamped, or
desoldered.
P = Spring, L = Locking Tab, S = Screw,
CN = Connector
* = Unhook, Unlock, Release, Unplug, or Desolder
e.g. 2(S-2) = two Screws (S-2),
2(L-2) = two Locking Tabs (L-2)
(5) Refer to “Reference Notes.”
Reference Notes
1. CAUTION: Locking Tabs (L-1) and (L-2) are
fragile. Be careful not to break them.
2. Remove five Screws (S-2). Then slowly lift the
VCR Chassis Unit (Deck Assembly and Main
CBA) up.
3. When reassembling, solder wire jumpers as
shown in Fig. D4.
4. Before installing the Deck Assembly, be sure to
place the pin of LD-SW on Main CBA as shown in
Fig. D5. Then, install the Deck Assembly while
aligning the hole of Cam Gear with the pin of LD-
SW, the shaft of Cam Gear with the hole of LD-SW
as shown in Fig. D5.
ID/
Loc.
No. Part
Removal
Fig.
No.
Remove/*Unhook/
Unlock/Release/
Unplug/Desolder Note
[1] Top Case D1 4(S-1) ---
[2] Front
Assembly D2 *3(L-1), *4(L-2) 1
[3] VCR Chassis
Unit D3 5(S-2) 2
[4] Deck
Assembly D4 D5 3(S-3), *Desolder 3 4
[5] Main CBA D4
D5 ---------- ---
↓
(1) ↓ (2) ↓ (3) ↓ (4) ↓ (5)
[1] Top Case
[2] Front Assembly
[3] VCR Chassis Unit
[4] Deck Assembly
[5] Main CBA
[1]Top Case
(S-1)
Fig. D1

1-5-2 HJ340DC
(L-2)
(L-1)
[2] Front
Assembly
(L-2)
Fig. D2
(S-2)
(S-2)
[3]VCR
Chassis Unit
Fig. D3
(S-3)
BOTTOMVIEW
From
FE Head
From
Cylinder
Assembly
From
ACE Head
Assembly
Lead with
blue stripe
Printing
side Lead with white stripe
From
Capstan
Motor
Assembly
Lead connections of Deck Assembly and Main CBA
Desolder Desolder
Fig. D4
(S-3)
(S-3)
[4] Deck
Assembly
FE Head Cylinder
Assembly
ACE Head
Assembly
[5] Main CBA

1-5-3 HJ340DC
[5] Main CBA
SW512
LD-SW
LD-SW Pin
Hole
Hole
Shaft
Cam Gear
[5] Main CBA
[4] Deck Assembly
Pin
Fig. D5

1-6-1 U29.5NEA
ELECTRICAL ADJUSTMENT INSTRUCTIONS
General Note: “CBA” is abbreviation for
“Circuit Board Assembly.”
NOTE:
1. Electrical adjustments are required after replacing
circuit components and certain mechanical parts.
It is important to do these adjustments only after
all repairs and replacements have been
completed. Also, do not attempt these adjustments
unless the proper equipment is available.
2. To perform these alignment / confirmation
procedures, make sure that the tracking control is
set in the center position: Press either [CHANNEL
L] or [CHANNEL K] button on the front panel first,
then the [PLAY] button on the front panel.
Test Equipment Required
1. Oscilloscope: Dual-trace with 10:1 probe,
V-Range: 0.001~50 V/Div.,
F-Range: DC~AC-20 MHz
2. Alignment Tape (FL8A)
How to Reset Software
To reset software, unplug the AC cord from the AC
outlet. Then, insert the AC cord again 30 seconds
later.
Head Switching Position
Adjustment
Purpose: To determine the Head Switching position
during playback.
Symptom of Misadjustment: May cause Head
Switching noise or vertical jitter in the picture.
Note: TP751(V-OUT), TP302(RF-SW),
VR501(Switching Point) --- Main CBA
Reference Notes:
Playback the Alignment tape and adjust VR501 so that
the V-sync front edge of the CH1 video output
waveform is at the 6.5H ± 1H (412.7 µs ± 63.5 µs)
delayed position from the rising edge of the CH2 head
switching pulse waveform.
Test point Adj. Point Mode Input
TP751(V-OUT)
TP302(RF-SW)
GND VR501
(Switching Point) PLAY (SP) -----
Tape Measurement
Equipment Spec.
FL8A Oscilloscope 6.5H ± 1H
(412.7µs±63.5µs)
Connections of Measurement Equipment
Figure 1
Oscilloscope
Main CBA TP751
CH1 CH2
Trig. (+)
GND
TP302
EXT. Syncronize Trigger Point
1.0H
CH1
CH2
Switching Pulse
V-Sync
0.5H
6.5H±1H (412.7µs±63.5µs)

1-7-1 HJ455FIS
FUNCTION INDICATOR SYMBOLS
Note: The following symbols will appear on the indicator panel to indicate the current mode or operation of the
VCR. On-screen modes will also be momentarily displayed on the tv screen when you press the operation
buttons.
Display panel
“H” = LED Light on, “L” = LED Light off
LED Mode Indicator Active
POWER Power on = “H”
Power off = “L”
VCR/TV VCR mode = “H”
TV mode = “L”
TAPE IN Cassette in = “H”
Cassette out = “L”
TIMER Timer stand by = “H”
One touch recording = “H”
Timer recording = “H”
General mode = “L”
REC REC mode = “H” REC pause
General mode = “L” Blinks at 0.8Hz interval
POWER VCR/TV TIMERTAPE IN REC

1-7-2 HJ455FIS
TV screen
Note: OSD for mechanical error will be displayed for 5 sec. after the mechanical error occurs.
When reel or capstan mechanism is not functioning
correctly
When tape loading mechanism is not functioning
correctly
When cassette loading mechanism is not functioning
correctly
When the drum is not working properly
Cause Indicator Active
When reel or capstan mechanism is not
functioning correctly “EJECT AR” is displayed on a TV screen. (Refer to Fig. 1.)
When tape loading mechanism is not
functioning correctly “EJECT AT” is displayed on a TV screen. (Refer to Fig. 2.)
When cassette loading mechanism is not
functioning correctly “EJECT AC” is displayed on a TV screen. (Refer to Fig. 3.)
When the drum is not working properly “EJECT AD” is displayed on a TV screen. (Refer to Fig. 4.)
EJECT AR
Fig. 1
EJECT AT
Fig. 2
EJECT AC
Fig. 3
EJECT AD
Fig. 4

1-8-1 U29.5L4HTR
POWER SUPPLY TROUBLESHOOTING GUIDE
It is highly recommended that a variable isolation
transformer which can monitor current be used.
(Alternatively a variable AC source which monitors
current will do). Read directions below before
power is added!
Repair method #1
(Power must be off)
1] Short circuit in the secondary side. Check diode
D021, D015, D016, and D020, switching FET (Q001),
control transistor (Q002), diode (D006), and resistor
(R014) replace as necessary.
Disconnect 44V diode (D021), 12V diode (D015), 5V
diode (D016), and 12V diode (D020). Check the load
continuity of 44V line, 12V line, and 5V line through a
tester (resistance range).
If the tester indicates a lower resistance value around
0 ohm, the line is short-circuited.
Before repairing the switching 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 load is short-circuited and there is
no problem.
2] Check for any defective parts while the secondary
rectifying diodes are disconnected D021, D015, D016,
and D020 perform a diode check in both forward and
reverse directions through a tester.
3] Remove the following components and check for
defects: snubber diode (D051), switching FET (Q001),
source resistor (R014), and control transistor (Q002).
Repair method #2
Check the fuse 1.0A (F001), primary rectifying diodes
(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 possible 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 steps 1] and 2] of
repair method #1 and check the following parts:
(Remove the part from PCB)
Switching FET (Q001), source resistor (R014), gate
resistor (R008), and start resistor (R004 and R005).
Repair method #3
A circuit to turn on switching FET (Q001) may not work
and this may be regarded as a cause 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. Therefore, perform check according
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 (R014), control
shunt regulator (Q031), gate resistor (R008), and start
resistor (R004 and R005).
Repair method #4
The feedback circuit which is monitored by the output
of voltage may not work and this may be regarded as
a possible cause, remove control transistor Q002 and
check for defects. More over, a photo coupler (IC001)
and transistor (Q031) 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 trouble. If there is no
output voltage on the secondary side, the rectifying
diodes (D021), (D015), and (D020) may be defective.
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 1.0 amps),
then turn off supply and do repair
method #1.
Check whether the primary rectifying
DC of the Switching power supply
has an output. (Reading should be
about 168V.)
Repair method
Although the secondary 5V is
working, are any of the other
voltages higher than normal (44V
and 12V voltages)?
With the primary DC working check
the secondary 5V.
Are the 44V, 12V and 5V lines
higher than normal?
There is no problem on the SW
power supply.
NO
YES
YES
NO
NO
#1
#2
#3
#4
#5
YES
NO
NO
YES
YES
CHECK

1-9-1
BLOCK DIAGRAMS
Servo/System Control Block Diagram
HJ45WBLS
M
LOADING MOTOR
SENSOR CBA SENSOR CBA
CAPSTAN MOTOR
CONTROL HEAD
CL504
CN502
CN504
ACE HEAD ASSEMBLY
MAIN CBA
KEY- 2
RF-SW
C-FG
C-CONT
D-PFG
ST-S T-REEL
C-F/R
KEY- 1
D-V SYNC
C-SYNC
V-ENV
REMOCON-IN
CTL(+)
RESET
C-ROTA
D-REC-H D-REC-H
REC- SAF-SW
PG-DELAY
RF-SW
D-V SYNC
C-SYNC
V-ENV
YCA-SCL
C-ROTA
END-S
IC501 (SERVO/SYSTEM CONTROL)
5
47
56
CTL
58
CTL(-)
57 28
49
69 62
3
20
27
65
18 78 64 19 41 14
2
24
7
66 67
RS501
REMOTE SENSOR
LM-FWD/REV
21
D-CONT
29
(DECK ASSEMBLY)
END-S
T-REEL
T-REEL
ST-S
ST-S
Q504
Q503
Q501
RESET
Q506
SW-POINT
AL+5V
VR501
TIMER+5V
TP506
TP505
YCA-SCL YCA-SDA
15
YCA-SDA
P-ON-L
22
P-ON-L P-DOWN-L
1
P-DOWN-L
H-A-SW
79
H-A-SW H-A-COMP
80
H-A-COMP
16
YCA-CS YCA-CS
SW511
REC SW
TO VIDEO BLOCK DIAGRAM TO AUDIO BLOCK DIAGRAM
TO Hi-Fi AUDIO BLOCK DIAGRAM
CLOCK DATA
TU701(TUNER UNIT)
11 12
VCR/TV
5
TIMER-IND
72
VCR/TV-IND
77
REC-IND
70
REC-IND
71
D564 TIMER
D563 CAS
D562 VCR/TV
D565 REC
D561 POWER
P-ON+5V
P-ON+9V
Q561
AL+5V
LD-SW
68
AL+12V
AL+5V
CAS-IND
74
TIMER-IND
73
AL+5V
SW512
AL+12V AL+18V
P-ON+5V
LD-SW
AL+5V
D555 S-LED
TO POWER SUPPLY BLOCK DIAGRAM
IIC-BUS SCL
IIC-BUS SDA
12 13
IIC-BUS SCL
IIC-BUS SDA
NORMAL-H
ST/SAP-MODE
61 59
Hi-Fi-H-SW
Hi-Fi/NOR-IN
ST/SAP-IN
Hi-Fi-H-SW
25
KEY SWITCH KEY SWITCH
TP502
S-INH
5 CTL(+) 6 CTL(-)
1
AL+12V
2
P-ON+5V
3
C-FG
4
C-F/R
5
C-CONT
6
GND
7
LM-FWD/REV
8
D-CONT
9
D-PFG
10
GND
11
AL+12V
12
AL+18V
TP513
CTL
END-S
TP507
63
AFC
13
AFC
YCA-SCL
YCA-SDA
YCA-CS
DRUM MOTOR
CYLINDER ASSEMBLY
PG SENSOR
M
AUDIO-MUTE-H AUDIO-MUTE-H
AUDIO-MUTE-H
M
CAPSTAN MOTOR
MOTOR DRIVE CIRCUIT
WF6
WF7

1-9-2
Video Block Diagram
HJ45WBLV
LUMINANCE
SIGNAL PROCESS
MAIN CBA
VIDEO (R)-1 HEAD
VIDEO (L)-1 HEAD
(DECK ASSEMBLY)
JK751
Q391
JK753
TP751
V-OUT
TU701
(TUNER UNIT)
VIDEO IN
VIDEO OUT
6
18
JK752
VIDEO
AGC
TUNER FRONT
REAR
RP
R
P
SYNC
SEPA
FBC
Y/C
MIX
CCD 1H
DELAY
R
P
YNR/COMB FILTER
CHROMINANCE
SIGNAL PROCESS
IC301
(VIDEO SIGNAL PROCESS/ HEAD AMP)
26
REC VIDEO SIGNAL PB VIDEO SIGNAL MODE: SP/REC
57
32 30
QV/QH
6dB
AMP
TO SERVO/SYSTEM CONTROL BLOCK DIAGRAM
TO SERVO/SYSTEM CONTROL BLOCK DIAGRAM
CYLINDER ASSEMBLY
RF-SW
RF-SW
59
V-ENV H-A-SW H-A-COMP H-A-COMP
TP302
VIDEO (L)-2 HEAD
VIDEO (R)-2 HEAD
TP301
C-PB
BUFFER
D-V-SYNC C-SYNC
D-V-SYNC
25 53 24
YCA-SCL
14
36 37 39 34
Q301
BUFFER
28
58 60
SP EP
54
YCA-SDA
55
YCA-CS
IC501 (OSD)
40
38
OSD CHARACTER MIX
SERIAL
I/F
VCA CLAMP
69 70
SP HEAD AMP
EP HEAD AMP
72 73 74 65 66 67
ENV-DET
C-ROTA
C-ROTA/RF-SW
WF1
WF2
WF3
REAR FRONT
REAR
CN253
VIDEO -IN VIDEO -IN VIDEO -OUT
VIDEO(R)-1
VIDEO-COM
VIDEO(L)-1 VIDEO(L)-2
VIDEO-COM
VIDEO(R)-2
1 2 3 4 5 6
WF5 WF9

1-9-3 HJ45WBLA
Audio Block Diagram
TU701(TUNER UNIT)
AUDIO-IN
REC AMP
SERIAL I/F
9
8
AUTO BIAS
11
P-ON+5V
P-ON+5V
Q421
BIAS OSC
Q422
Q426 (PB=ON)
Q425
SWITCHING D-REC OFF
6
5
3
EQ AMP
LINE AMP MUTE 10
2
SP/LP-ON
P
R
ALC
REAR TUNER
FRONT
IC301 (AUDIO SIGNAL PROCESS) 76
2
SIF OUT 15
TP753 A-OUT(R)
TP754 A-OUT(L)
4
AUDIO-PB/REC
CN504
3 A-COM 1 AE-H 2 AE-H/FE-H
AUDIO HEAD AUDIO ERASE HEAD
ACE HEAD ASSEMBLY
FE HEAD
(DECK ASSEMBLY)
1 FE-H 2 FE-H-GND
CN501
MAIN CBA
PB-AUDIO SIGNAL REC-AUDIO SIGNAL Mode : SP/REC
55 54 53
D-REC-H
YCA-CS
YCA-SDA
YCA-SCL
TO SERVO/SYSTEM CONTROL BLOCK DIAGRAM
FULL ERASE HEAD
7880
4
SIF
N-A-OUT
N-A-IN
JK751 JK752 JK754 JK755
TO Hi-Fi AUDIO BLOCK DIAGRAM
FRONT
REAR
LPF
58
AUDIO-MUTE-H
MOD-AUDIO
AUDIO(R)-IN-F
AUDIO(L)-IN-F
AUDIO(L)-IN
AUDIO(R)-IN
AUDIO(R)-OUT
AUDIO(L)-OUT
AUDIO(R) -IN AUDIO(L) -IN AUDIO(R) -OUT AUDIO(L) -OUT AUDIO(R) -IN AUDIO(L) -IN
WF4