FUNAI 31A-250, 31D-250, 31C-250 Service Manual
SERVICE MANUAL
Main Section
I Specifications
I Preparation for Servicing
I Adjustment Procedures
I Schematic Diagrams
I CBA’s
I Exploded views
I Parts List
When servicing the deck
mechanism, re fer to MK14 Deck
Mechanism Section.
Deck Mechanism Part No.:
31A-250/31D-250: N25A0FL
31C-250: N25A1FL
VIDEO CASSETTE RECORDER
SECAMPAL
31A-250/31D-250
31C-250
PAL
MAIN SECTION
VIDEO CASSETTE RECORDER
31A-250/31C-250/31D-250
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
How to Initialize the VCR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7-1
Function Indicator Symbols. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-8-1
Block Diagrams. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-9-1
Schematic Diagrams / CBA’s and Test Points. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-10-1
Waveforms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-11-1
Wiring Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-12-1
IC Pin Function Descriptions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-13-1
Lead Identifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-14-1
Exploded Views. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-15-1
Mechanical Parts List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-16-1
Electrical Parts List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-17-1
Sec. 1: Main Section
I Specifications
I Preparation for Servicing
I Adjustment Procedures
I Schematic Diagrams
I CBA’s
I Exploded Views
I Parts L ist
1-1-1 HM340SP
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 repres ent the absolute worst condi tion 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 FL6A
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 37 41 SP Mode
1-5. Video Color S/N PM (R/P) dB 30 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 200Hz dB -7 -4 SP Mode
(-20dB ref. 1kHz) at 6kHz dB -10 -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
1-2-1 U31P_ISP
IMPORTANT SAFETY PRECAUTIONS
Product Safety Notice
Some electrical and mechanical parts have special
safety-related characteristic s 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 cha racteristics are
identifi ed b y 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 electr ical codes of the
countries in which they are to be sold. However, in
order to maintain suc h c omp li anc e, it is equally imp or tant 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 spur ious radiati on. Thes e must also be
replaced only with specified replacements.
Examples: RF converter s, 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 tubin g
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 no t contact heat produc-
ing parts (hea tsinks, oxide metal film resi stor s, fusible resistors, etc.).
G. Check that replaced wires do not contact sharp
edges or pointed parts.
H. When a power cord has been replac ed, 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 insu lation 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 complet e closure of the tool.
L. When connecting or disconnecting the internal
connectors, first, disconne ct the AC plug from the
AC outlet.
1-2-2 U31P_ISP
Safety Check after Servicing
Examine the area surrounding the repaired location
for damage or deterioration. Observe that screws,
parts, and wires have been returne d 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 distanc e (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 Curren t 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 (Po wer ON) :
Insert load Z between B (earth ground, power cord
plug prongs) and exposed accessible parts. Use an
AC voltmeter to measure across t he ter minals of l oad
Z. See Fig. 2 and the following table.
AC Line Voltage Clearance Distance (d), (d’)
220 to 240 V
≥ 3mm(d)
≥ 6 mm(d’)
Fig. 1
Chassis or Secondary Conductor
Primary Circuit
d' d
AC Voltmeter
(High Impedance)
Exposed Accessible Part
B
One side of
Power Cord Plug Prongs
Z
Fig. 2
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 Load Z Leakage Current (i)
One side of power cord plug
prongs (B) to:
220 to 240 V
2kΩ RES.
Connected in
parallel
i≤0.7mA AC Peak
i≤2mA DC
RF or
Antenna terminals
50kΩ RES.
Connected in
parallel
i≤0.7mA AC Peak
i≤2mA DC
A/V Input, Output
1-3-1 VCRP_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 pa ck-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 chi p par ts 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 t o protect other pa r ts from
damage. (Fig. S-1-2)
T op Vie w
Out
In
Bottom View
Input
5
10
Pin 1
Pin 1
Fig. S-1-1
1-3-2 VCRP_SN
3. The flat pack-IC on the CBA is affixed with glue, so
be careful not to br eak or dam age the foil of each
pin or the solder lands under the IC when
removing it.
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 applie d to all pi ns 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 wi re to which sold er will
not adhere (iron wire). W hen hea tin g the pi ns, use
a fine tip soldering iron or a hot air desoldering
machine. (Fig. S-1-4)
3. Bottom of the flat pa ck-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)
Hot-air
Flat Pack-IC
Desoldering
Machine
CBA
Flat Pack-IC
Tweezers
Masking
Tape
Fig. S-1-2
Flat Pack-IC
Desoldering Braid
Soldering Iron
Fig. S-1-3
Fine Tip
Soldering Iron
Sharp
Pin
Fig. S-1-4
1-3-3 VCRP_SN
With Iron Wire:
1. Using desolder ing braid, remove the solder from
all pins of the flat pack-IC. When you use solder
flux which is appl ied 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.
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 rep la cem ent fl at p ack-IC more
easily.
2. The “●” mar k on the flat pack-IC indicates pin 1.
(See Fig. S-1-7.) Be su re this mar k m atches t he 1
on the PCB when positioni ng for installation . Then
presolder the four corners of th e fl at pa ck-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.
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
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
1-3-4 VCRP_SN
Instructions for Handling Semiconductors
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 elec trici ty that
may be charged on the body.
2. Ground for Workbench
Be sure to place a condu ctive 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.
<Incorrect>
CBA
Grounding Band
Conductive Sheet or
Copper Plate
1MΩ
1MΩ
<Correct>
CBA
1-4-1 HM4N0PFS
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 Asse mbly and
press the PLAY button. The tape will be loaded into
the Deck Mechanism Assembly. Make sure the power
is on, connect TP507 (S- INH) to GND. This will stop
the function of Tape Start Sensor, Tape En d Sensor
and Reel Sensors. (If these T Ps ar e con nec ted 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 al l t he way to the start or the end of the
tape to avoid tape damage.
Fig. 1
TP507
S-INH
Q504
Q505
1-5-1 HM340DC
CABINET DISASSEMBLY INSTRUCTIONS
1. Disassembly Flowchart
This flowchar t indi cates the di sass embly ste ps to ga in
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
(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
CAUTION: Locking Tabs (L-1) and (L-2) are fragile.
Be careful not to break them.
1. Remove five Screws (S-2), three Screws (S-3) and
Screw (S-4). Then, slowly lift the VCR Chassis Unit
(Deck Assembly, Jack CBA and Main CBA) up.
2. When reassembling, solder wire jumpers as shown
in Fig. D5.
3. Before installing the Deck Assembly, be sure to
place the pin of LD-SW on Main C BA as shown in
Fig. D6. Then, install the Deck Assembly while
aligning the hole of Cam Gear with the pin of LDSW, the shaft of Cam Gear with the hol e of L D- SW
as shown in Fig. D6.
ID/
LOC
.No.
PART
REMOVAL
Fig.
No.
REMOVE/*UNHOOK/
UNLOCK/RELEASE/
UNPLUG/DESOLDER
Note
[1] Top Case D1 7(S-1) -
[2]
Front
Assembly
D2 *3(L-1),*4(L-2) -
[3]
VCR Chassis
Unit
D3 5(S-2), 2(S-3), (S-4) 1
[4] Jack CBA D4 Desolder, (S-5) -
[5]
Deck
Assembly
D5
D6
(S-6A),(S-6B), Desolder 2,3
[6] Main CBA D 5 ---------- -
[7]
Cylinder
Shield
D5 (S-7) -
↓
(1)
↓
(2)
↓
(3)
↓
(4)
↓
(5)
[5] Deck Assembly
[4] Jack CBA
[1] T op Case
[2] Front Assembly
[3] VCR Chassis Unit
[6] Main CBA
[7] Cylinder Shield
Fig. D1
(S-1)
(S-1)
(S-1)
[1] T op Case
1-5-2 HM340DC
Fig. D2
(L-2)
(L-1)
[2] Front
Assembly
(L-2)
Fig. D3
(S-2)
(S-2)
(S-4)
(S-2)
(S-2)
(S-3)
(S-3)
[3]VCR
Chassis
Unit
Fig. D4
(S-5)
[4] Jack CBA
Desolder
1-5-3 HM340DC
(S-7)
[5] Deck
Assembly
FE Head
Cylinder Assembly
ACE Head
Assembly
[7] Cylinder Shield
[6] Main CBA
(S-6A)
(S-6B)
From
FE Head
From
Cylinder
Assembly
From
ACE Head
Assembly
Lead with
white stripe
Lead with
blue stripe
Desolder
from bottom
Lead with
blue stripe
From
Capstan Motor
Assembly
Lead connections of Deck Assembly and Main CBA
Printing
side
TOP VIEW
Fig. D5
Fig. D6
[6] Main CBA
SW507
LD-SW
LD-SW
Pin
Hole
Hole
Shaft
Cam Gear
[6] Main CBA
[5] Deck Assembly
Pin
1-6-1 FEGVCREA
ELECTRICAL ADJUSTMENT INSTRUCTIONS
General Note: "CBA" is an abbreviation for
"Circuit Board Assembly."
NOTE:
1.Electri cal adjustm ents are re quired after re placing
circuit components and certain mechanical par ts.
It is importan t 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 per form these alignmen t / confirmation pro cedures, make sure that the tracking control is set in
the center position: Press either "CHANNEL L5??" or
"CHANNEL K" button on the remote control unit
first, then the "PLAY" button (Front Panel only).
Test Equipment Required
1.Oscilloscope: Dual-trace with 10:1 probe,
V-Range: 0.001~50V/Div.,
F-Range: DC~AC-20MHz
2.Alignment Tape (FL6A)
Head Switching Position Adjustment
Purpose:
To deter mine the Head Switching position during
playback.
Symptom of Misadjustment:
May cause Head Switching noise or vertical jit ter
in the picture.
Reference Notes:
Playback the Alignment tape and adjust VR501 so that
the V-sync front edge o f the CH1 video output waveform is at the 6.5H±1H (416µs±64µs) delayed position
from the rising edge o f the CH2 head switching pulse
waveform.
Test point Adj.Point Mode Input
J23(V-OUT)
TP502(RF-SW)
GND
VR501
(Switching Point)
(MAIN CBA)
PLAY
(SP)
-----
Tape
Measurement
Equipment
Spec.
FL6A Oscilloscope
6.5H±1H
(416µs±64µs)
Connections of Measurement Equipment
Figure 1
Oscilloscope
Main CBA
J23
CH1 CH2
Trig. (+)
GND
TP502
EXT. Syncronize Trigger Point
1.0H
CH1
CH2
Switching Pulse
6.5H+/-1H (416µs+/-64µs)
V-Sync
0.5H
1-7-1 HM340INT
HOW TO INITIALIZE THE VCR
To put the program back at the factory-default,
initialize the VCR as the following procedure.
1. Make sure that no timer programming is set. If not,
reset all timer programming.
2. Turn the power off.
3. Press the [STOP/EJECT] button and
[CHANNEL K] button on the unit simultaneously
for at least 2 seconds.
4. Release the [STOP/EJECT] button and
[CHANNEL K] button to complete this mode.
1-8-1 HM240FIS
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
MODE INDICATOR ACTIVE
STANDBY
VEILLE
Always " H " during electricity
FUNCTION
FONCTION
Power on = " H "
Power off = " L "
TAPE IN
CASSETTE
Cassette in = " H "
Cassette out = " L "
TIMER
MINUTERIE
Timer stand by = " H "
One touch recording = " H "
Timer recording = " H "
General mode = " L "
REC
ENR.
REC mode = " H "
REC pause
General mode = " L "
Blinks at 0.8Hz interval
TAPE IN TIMER RECFUNCTIONSTANDBY
31A-250 / 31D-250
31C-250
CASSETTE MINUTERIE ENR. FONCTIONVEILLE
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