Sanyo M7770K User manual

MINI STEREO CASSETTE
RECORDER
ee
eae
SoAN YO
Power Source
Ee ee a as 9 ({UM-2: HP11, ¢ Cell,
Babyzelle, R14) x 6
Output: Power 2 2 oe eee: 3.5W x 2 (Max.)
Power GonsumplOn vee eee es OW
Current Consumption (at Vol. Min.)
Record mode... oe eee. 265mA
Playback mod6 .. oye ee 175mA
Fast Forward mode. 2 vec 155mA
Rewind mode csc. sk e. 165mA
Recording System. se AG Blas
Erasing SYStOM oc lise eh ee ge AC Erasing
ape Sheed 2 ee 1-7/8 10s. £3%
Wow & Flotiere ie eee 0.15% WRMS
Fast: Forward Time: 22 eee. 110sec. (with C-60)
Rewtnd: Pime:oisoee ieee ie 110sec. (with C-60)
Frequency Response (Overall)
PO2 O39 solo ee AQHz ~ 13,000 Hz
CHO2 ee. 40Hz ~ 14,000 Hz
Metab: oe es AOHz ~ 16,000 Hz
Erase Ratio (Overall, with Fe203). .
Crosstalk (with Fe203)
TACK AO VEC este hee aoe :
Hume&:Notse (at Volo Mins) oc oe.
Input Sensitivity and Impedance
MIC,
Ee ec Se
NN eee
Output Level and |mpedance
PEN UE ee a
EXT SDeaker 1) ou en
Headphone eve ee ik ee ;
Frequency Range
MW
a Ser i ae Se a, Se ce ed
ee a a a ch i se ee J
a ee a a, Se ee ce eo
—Specifications subject to change without notice.—
142 340 24 |
. 60dB
Signal to Noise Ratio (with Fe203) ..
48dB
50dB
—60dBs
0.3mV/3.3ki2
100mV/100k22
300 mV/2.2 kad
2~ 3202
32 82
525 ~ 1 ,605kHz
2.3~7.3MHzZ
AS ~ 2ZBMAZ
88 ~ 108MHz
WM-3000

DISASSEMBLY INSTRUCTIONS
GENERAL REMARKS
Before disassemblying the unit, spread a soft cloth or a
rubber mat on the work bench to avoid scratches and grease
stains.
Do not spread anything which is likely to cause static
electricity because transistors and |Cs are easily broken by it.
Correctly reassemble the unit, noting the kinds of fastening
screws and the lead arrangement. Please refer to ‘’Schematic
Diagrams” and ‘‘Exploded Views”.
CABINET BOTTOM ASSEMBLY REMOVAL
1.
Take out the cassette tape from the compartment by
pressing the STOP/EJECT button.
Remove the battery compartment lid and take out the six
batteries from the compartment. Then, remove the seven
screws (1 — 7) fastening the Cabinet Bottom.
Pull out the connector of the antenna from the Radio Tuner
P.C.Board. Then, remove the Cabinet Bottom by lifting it in
the direction of the arrow.
Cabinet Bottom
4. Reassemble in reverse order.
RADIO CHASSIS ASSEMBLY REMOVAL
1. After removing the Cabinet Bottom, pull out the volume
control, tone control, balance control, and tuning knobs
from the unit.
Balance Control Knob
Volume Control Knob
Tuning
Knob
8
Tone
Control
Knob
Connector (TP6)
Connector (CN5)
2.
Pull
out
Connector
CN5
from
the
Amplifier
P.C.Board
and
then,
Connector
TP6
from
the
Radio
Tuner
P.C.Board.
3. Remove the screw (8) fastening the Radio Chassis.
4.
Remove
the
Radio
Chassis
by
lifting
it
in
the
direction
of
the arrow.
Radio Chassis
5. Reassemble in reverse order.
a ae

DISASSEMBLY INSTRUCTIONS (Continued)
AMPLIFIER P.C.BOARD ASSEMBLY REMOVAL RADIO TUNER P.C.BOARD REMOVAL
1.
Follow
the
instructions
for
the
Cabinet
Bottom
Assembly
1.
Follow
the
instructions
for
the
Radio
Chassis
Assembly
Removal.
Removal.
2. Pull out Connector CN3 from the P.C.Board and remove 2. Turn the Tuning Knob fully in an arbitrary direction.
the leads from the Volume P.C.Board.
3. Remove the screws (10 and 11) fastening the Radio Tuner
P.C.Board. Then, detach the P.C.Board by lifting it in the
direction of the arrow.
Radio Tuner P.C.B.
Radio
Chassis
.
4.
Reassemble
in
reverse
order.
Amplifier P.C.B. NOTE:
Do not turn the Tuning Knob before the Radio Tuner
P.C.Board is re-mounted to the unit.
When the Radio Tuner P.C.Board is mounted, insert the
shaft of the variable capacitor into the hole on the drum.
After that, check to see that correct dial indications are
obtained.
3. Carefully remove the P.C.Board by lifting it in the numerical MECHANISM CHASSIS REMOVAL
order
as
illustrated.
1.
Remove
the
Radio
Chassis
from
the
unit
by
following
its
removal instruction and then, a screw (9) fastening the
Amplifier P.C.Board.
Amplifier P.C.B.
2. Remove the two screws (12 and 13) fastening the AMSS
Program P.C.Board and then, the P.C.Board.
3. Remove the four screws (14 — 17) fastening the Chassis and
the two screws (Red and Black) running from the motor.
4. Remove the Mechanism Chassis by lifting it in the direction
of the arrow. Note the lead connections.
4. Reassemble in reverse order. 5. Reassemble in reverse order.

DISASSEMBLY INSTRUCTIONS (continuea)
CASSETTE COMPARTMENT LID REMOVAL
sem
C
:
-
1,
Open
the
cassette
compartment
lid
by
pressing
the
Mechanism Chassis STOP/EJECT button.
2. Unlock the compartment latches from the Cabinet Top by
pushing the both sides of the compartment lid strong. Then,
the lid will be easily removed from the unit.
Leads (Red and Black)
Mechanism Chassis
Cassette Compartment Lid
3. Reassemble in reverse order.
NOTICE ON REASSEMBLY
1. Refer to ‘Wiring Diagram”’ for re-wiring.
2. Refer to ‘Exploded Views”’ for lead arrangement.
3. Check to see that the lead wires or electrical components do
not touch the driving mechanism.

ADJUSTMENTS
GENERAL REMARKS
@ Before adjustment, wipe the tape contacting surfaces clean
as well as the contacting surfaces of the driving parts with a
soft cloth soaked in alcohol. Trouble may occur because of
oil and grease stains.
@ Carefully handle the belt because grease easily attaches to it.
@ Check the rubber-used parts. If the rubber has quality
deterioration or scratch marks, replace the part with a new
one,
Unless especially specified, set the unit and measuring
instruments as follows:
@ Tape Select Switch............ 0202 eae NORMAL
@ Function SWItth « 664.454.0404 555.456.549.484 4 TAPE
@: Mode: SWitthwes se eS oe ee lw ee Ree STEREO
@ Beat Cancel Switch ......... 0.0 eee ee ee ee 3
@ Balance Control.............. Center (click position)
©. “Tone CoOntrGl: «405-3 4.2.2.6 hw ee ee we a High
©: Nolime Control’ <s-004 Ss yee ke ee Ne eee ows Arbitrary
@® DC Constant-Voltage Regulator Output ....... 9.0V DC
NOTE:
1. Perform each adjustment in the described order.
2. Obtain the output from the line output terminal.
3. Supply 9.0V DC from the constant-voltage regulator to
the unit.
EQUIPMENT REQUIRED
@ VTVM (2 sets)
Frequency Counter
Dummy Load (47 k-ohm)
Dualtrace Synchroscope
Test Tapes
* 3kHz Test Tape (Example: TEAC MTT-111) for Tape
Speed Adjustment
* 8kHz Test Tape (Example: TEAC MTT-113C) for Head
Azimuth Adjustment
@ DC Constant-Voltage Regulator
@ Alignment Tool
AMSS SOLENOID ADJUSTMENT
AMSS (Automatic Music Select System) detects a silent space
(unrecorded portion) between each music on a music tape and
automatically plays back a desired music from the start.
NOTE:
Unrecorded portion should last more than approximately four
seconds.
It may not operate correctly in the following cases:
* When the recorded sound is often interrupted as in a speech
tape.
When the silent space does not last long enough (less than
four seconds).
When there is an appreciable noise in the silent space
between two adjacent programs.
When the unit is placed on a television set, AMSS may not
Operate correctly due to adverse effect of the TV signal. In
this case, put the unit away from the television set.
*
If
AMSS
Solenoid
is
not
correctly
positioned,
AMSS
mechanism
does not function correctly, F.FWD or Rewind button is released
while
Automatic
Music
Select
System
is
working,
or
a
button
may not be locked. In this case, perform the adjustment as
follows:
1.
Remove
the
Chassis
from
the
unit
by
following
its
removal
instructions.
2. Loosen the two screws fastening the Spacer of the Solenoid.
Then, adjust the Spacer by moving it in the direction of the
arrow, so that the Lock Plate is tightly attached to the two
absorption surfaces as illustrated.
Spacer
Screw
(ime wae seme
ee) ae
No Clearance
3. After the adjustment, tighten the screws fastening the
Spacer. Set the unit in the playback mode and check that
AMSS mechanism functions correctly as follows:
* Check if F.FWD button can be locked by pressing it.
* Check if Rewind button can be locked by pressing it.
4. Readjust the spacer position if either F.FWD or Rewind
button cannot be locked or is soon released.
5. After the confirmation, secure the screws fastening the
Spacer with paint or glue. —

ADJUSTMENTS (Continued)
TAPE SPEED ADJUSTMENT
1. Remove the cassette compartment lid and connect a
frequency counter to the left or right channel LINE OUT as
illustrated. Then, play back a 3kHz test tape (Example:
TEAC MTT-111).
Frequency Counter
3000 Hz (+3 %)
Dummy Load
47k ohm
LINE OUT
2. Adjust the tape speed by turning the potentiometer inside
the Motor with an alignment tool until the frequency
counter reads 3kHz (+10Hz).
Tape Speed Adjustment
HEAD AZIMUTH ADJUSTMENT
1. Remove the cassette compartment lid and connect a VIVM
and a dualtrace synchroscope to both channels LINE OUT
as illustrated. Set the synchroscope as follows:
PV OES tis og: i astas Oy Se ae ene SO te eee oe CHOP
PP «OIA ACESS 1k Fak he tlhe Sata See hho in INT. (CH1 or CH2)
7 SVWVGER MODE. fgscicewtee dot eras AUTO (automatic) -
Azimuth Adjusting Screw
Synchroscope
Dummy Load
47k ohm
LINE OUT
© ©
Oy
Dummy Load
47k ohm
Insert a 8kHz test tape (Example: TEAC MTT-113C) into
the cassette compartment and play it back.
_ Slowly turn the azimuth adjusting screw until the amplitudes
of both channel signal wave forms are at maximum and both
wave forms overlap. Set to optimum at maximum reading of
the VIVM.
Adjustment
R/P Head
| yumeanannees ateaeaneanillAninnan ne AIRMAN SAAN PANELED SIR AE POORER CHAO LE SOAPS SEAL SIAL
4.
After
the
adjustment,
secure
the
azimuth
adjusting
screw
with paint or glue.

TUNER ADJUSTMENT
Measuring Instruments Required
AM Signal Generator
FM Standard Signal Generator
Generator Scope
Stereo Signal Generator
Loop Antenna
Dummy Antenna (75 ohm, unbalanced type)
VTVM :
Frequency Counter
Distortion Meter
Oscilloscope
Dummy Load (3.2 ohm)
Alignment Tool
NOTE:
Use an alignment tool with plastic grip for all adjustments.
MW ALIGNMENT Standard test frequency 400 Hz and modulation 30% at AM
Alignment of Signal
INPUT OUTPUT Generator
455kHz Low End T3, T4 and T5
Tuning Dial
Setting Adjustments Remarks
Obtain symmetrical curve
and maximum amplitude.
Connect standard
loop antenna to
output terminal of
gene-scope.,
Connect input
terminal of gene-
scope to detector
Calibration
of IF
for AM Place bar antenna output.
60 cm away from (CN1-2 and CN1-1
loop antenna. or CN1-3)
Obtain sine-wave of 400Hz
and maximum amplitude.
Connect standard
loop antenna to
output of AM signal
generator.
Calibration
of
Tuning Range
Connect VT VM with
3.20hm dummy load
and oscilloscope to
Adjustment
Place bar antenna Phones/Ext. Speaker 600 kHz 600kHz | L4 (bar ant. coil)
of 60 cm away from terminal.
Tracking loop antenna. 1,400 kHz 1 400 kHz
Repeat the above steps until no further change is noted in any of the adjustment.
SW1 ALIGNMENT
Obtain sine-wave of 400Hz
and maximum amplitude.
Connect standard
Joop antenna to
output of AM signal
Calibration
of
Tuning Range
Alignment
:
of
Signal
Tuning
Dial
INPUT
OUTPUT
Generator
7.5MHz High End TC4
Connect VT VM with
3.20hm dummy load
generator. and oscilloscope to
Adjustment | Place bar antenna Phones/Ext. Speaker 2.5MHz 2.5MHz | L4-3 (bar ant. coil)
of 60cm away from terminal.
Tracking
6.5MHz 6.5MHz TC3 (PVC)
Repeat the above steps until no further change is noted in any of the adjustment.
loop antenna.

Frequency
TUNER ADJUSTMENT (Continued)
SW2 ALIGNMENT
Alignment Adjustments Remarks
INPUT OUTPUT Generator
Calibration | Connect AM signal oo Ed Obtain sine-wave of 400 Hz
of generator to antenna | Connect VTVM with and maximum amplitude.
a ae Range | terminals (TP1 or 3.20hm dummy load
TP2) and oscilloscope to
Adjustment | through dummy Phones/Ext. Speaker es [ ane [oe
of antenna terminal.
Tracking (300hm/10 pF).
Repeat the above steps until no further change is noted in any of the adjustment.
Tuning Dial
Setting
FM
ALIGNMENT
Standard
test
frequency
400Hz
and
deviation
22.5kHz
Tuning Dial ;
Obtain symmetrical curve
and maximum amplitude.
Turn T2 (blue core)
Connect output Connect input fully counter-
terminal of gene- terminal of gene- clockwise.
scope to pin 3 of scope to detector T1 Nd
Calibration 1C1 through output. ;
capacitor (10 pF) (CN1-2 and CN1-1 10.7 MHz Low End
or CN1-3) Obtain S curve and
maximum amplitude.
T2 (blue core)
Alignment of Signal
INPUT OUTPUT Generator
Calibration Connect FM signal | 87.2MHz 2MHz a a Obtain sine-curve and
of generator toantenna | Connect VT VM with maximum amplitude.
Tuning Range} terminals (TP1 and 3.20hm dummy load
TP2) through and oscilloscope to
Adjustment | dummy antenna. Phones/Ext. Speaker
of (750hm, unbalanced | terminal.
Repeat the above steps until no further change is noted in any of the adjustment.
FM MULTIPLEX ADJUSTMENT | 38kHz (V.C.0.) ADJUSTMENT
1.
Connect
the
frequency
counter
to
the
sixteenth
pin
(TP7)
in
Prior
to
the
adjustment,
set
the
unit
as
follows:
|C3
and
a
resistor
(330
k-ohm)
as
illustrated.
@ Function
Switch
...............
0005
RADIO
(ON)
@
Band
Select
Switch
...........
0.00.
FM
2.
Adjust
the potentiometer
(P1)
until
the
oscillation
frequency
@
Mode
Switch.............00
0c
eee
eee
STEREO
of IC3
becomes
38kHz
(+20Hz).
@
Balance
Control..............
Center
(click
position)
©
TOne
CON:
6a45no
sn
Gee
ea
Maximum
@
Volume
Control
.........
0...
cee
ee eee
ns
Center

DIAL CORD STRINGING
1. Mount the Radio Tuner P.C.Board on the Radio Chassis and 4. Hook the dial cord to the spring and tie the cord where the
then, the Drum to the shaft of the variable capacitor. spring tip extends until the spring length becomes
approximately 31mm.
2. Tie the dial cord of length 1,070mm (effective length:
950mm) and diameter $5 to the spring and hook the spring 5. Secure the place where the spring is hooked to the drum and
to the illustrated position of the drum. the knot in the dial cord with paint or glue.
3. Engage the dial cord as illustrated in the following order. 6. Turn the Tuning Shaft counterclockwise until it stops and
Drum == Pulley A == Pulley B ==> Pulley C ==> Tuning set the left edge of the pointer to the mark on the Radio
Shaft (3 turns) ==> Pulley D => Drum ==> Spring Chassis as illustrated. Then, fix the pointer there.
7. Apply white lacquer to the pointer to secure.
S Pointer init ‘
\
Dial Cord
Roller B
Soc
SS ee Tuning Shaft
3 Turns Radio Chassis
Pointer
Scratch Mark
about 31mm

Ref.
No.
CN3
CNS
CA1-
CAI
CA2
CA3
CA4
CAS
CA5
CA6
CA7
CA8
CA9
CA10
CA11
CA12
CA13
CA14
CA15
CA16
CA17
CA18
CA18
CA19
CA20
CA21
CA21
CA22
CA22
CA23
CA24
CA25
CA26
CX1
CX2
CX3
CX4
CX4
Part No.
PACKAGE
141
141
141
141
141
141
141
141
141
141
ACCESSORIES
141
141
2 1719 20300
6 1419 65001
6 1419 65004
6 1449 82300
6 1449 82400
6 2519 10021
6 2519 15290
6 2519 23033
6 3119 19300
6 4559 00100
4 1919 71480
4 2369 72251
4 2419 72492
6 4729 01900
6 4729 32400
142 6 4119 31632
CABINET
141
141
141
141
141
141
141
141
141
141
141
141
141
141
141
141
141
141
141
141
141
141
141
14]
141
141
141
141
141
4 2359 70990
4 2359 75727
4 2359 75758
0 1249 23201
0 1249 23204
2 8529 06200
2 1639 44300
2 1639 44200
0 1119 88801
0 1119 88804
2 4469 36500
2 1519 24700
2 1659 09300
2 1639 51100
2 1639 51000
2 4469 31700
2 1149 29200
4 1519 71084
2 2719 18500
Q 5519 08500
2 1659 09400
2 7419 77200
0 1719 10400
0 1719 10403
2 1149 29201
2 3729 00801
0 1339 09703
0 1339 09706
2 1119 84801
2 1119 84804
2 4219 09800
2 1649 12900
4 2449 70330
2 4729 03001
102 3 1303 01011
102 3 1302 60811
143 3 1303 03018
101
101
3 1302 60614
3 1302 60618
PARTS LIST
Description
Handle
Individual Carton (White)
Individual Carton (Blue)
Styrofoam Case, Left
Styrofoam Case, Right
Poly Cover 100 x 210
Poly Cover
Poly Cover 230 x 330
Reinforce Handle
Serial No. Sheet
AC Adaptor
Adaptor Plug Assy
Cassette
Caution Label
POP Label
Instruction Manual
RT Pin Socket
Connector 4P Assy -
Connector 3P Assy
Cassette Lid Assy (White)
Cassette Lid Assy (Blue)
Spring, Cassette Lid
Fine Tuning Knob
Tuning Knob
Cabinet Top Completed (Speaker (3002)
[SP102 & SP202] is Included ) (White)
Cabinet Top Completed (Speaker (3000)
[SP102 & SP202] is Included ) (Blue)
Cushion
Reflector
AMSS Button
Volume Knob
Tone Knob
Cushion, Mike
Screen, Speaker (Right)
Speaker (3.20) [SP101 & SP201]
Handle Holder
Eject Gear Assy
Rec. Mute Knob
Cassette Lid Lock
Handle Assy (White)
Handle Assy (Blue)
Screen, Speaker (Left)
Fix Speaker Bracket
Battery Lid Assy (White)
Battery Lid Assy (Blue)
Cabinet Bottom (White)
Cabinet Bottom (Blue)
Screw
Band Select Knob
Antenna Rod
Lug
Screw, Pan Hd. Tapping-1
Screw, Pan Hd. Tapping-1
Screw, Pan Hd. Tapping-B
Screw, Pan Hd. (White)
Screw, Pan Hd. (Blue)
+M3.0x10
+M2.6x8
+M3.0x30
+M2.6x6
+M2.6x6
Q’ty iar Part No. Description Q’ty
RADIO CHASSIS
1 DC1 141 2 8119 09701 Counter 1
4 DC2 141 2 5649 11700 Counter Belt 1
1 DC3. 141 2 8139 09500 Counter Bracket 1
1 DC4 141 2 8519 29400 Spring, Stop Lever 1
1 DC5 141 2 3519 57700 Bracket Eject Arm 1
1 DC6 141 2 4729 04000 Lug 1
1 DC7 141 2 2449 45400 Sheet 1
1 DC8 4 1329 78400 AMSS Program P.C.B. Assy [See PCB3] 1
1 DC9 141 2 8519 78000 Spring, Stop 1
2 DC10 141 2 5389 03400 Drum 1
DC11 4 2249 70300 ‘Fine Tuner ([FT1] 1
DC12 4 1329 78420 Jack P.C.B. Assy [See PCB6] 1
DC13. 141 2 3679 31501 Jack Plate (White) 1
1 DC1i3. 141 2 3679 31506 Jack Plate (Blue) 1
1 DC14 4 1539 70661 Microphone [BM1 & BM2] 2
1 DC15 141 2 4219 14000 Screw 4
1 DCi6 141 2 5519 03300 _Dial Roller A 3
1 DC17 = 141 2 3119 18100 Radio Chassis 1
1 DC18 141 2 1449 52900 Dial Plate (White) 1
DC18 141 2 1449 52902 Dial Plate (Blue) 1
DC19 141 2 8259 04700 _ Dial Roller 1
DC20 4 1329 78530 VolumeP.C.B. Assy [See PCB5] 1
2 DC21 141 2 3829 18000 Spring, Terminal 1
1 DC22. 141 2 5119 08100 ‘Pointer 1
1 DC23 4 1329 78410 LED Indicator P.C.B. Assy [See PCB4] 1
1 DC24 141 2 3829 06700 _—‘ Terminal Battery Anode 1
1 DC25 141 2 3829 20800 Spring, Battery 1
1 DC26 4 1259 71870 Radio Tuner P.C.B. Assy [See PCB2] 1
1 DC27 4 1329 78391 Amplifier P.C.B. Assy [See PCB1] 1
1 DC28 141 2 4469 42500 Cushion, Screen Switch 1
1 DC29. 141 2 2449 45100 Screen Switch 1
DC30 141 2 1629 06800 Function Knob 3
| DY1 102 3 1302 61411 Screw, Pan Hd. Tapping-1 +M2.6x14 3
DY2 101 3 1302 00311 Screw, Pan Hd. +M2.0x3 1
DY3 102 3 1302 60811 Screw, Pan Hd. Tapping-1 +M2.6x8 5
DY4 102 3 1302 60818 Screw, Pan Hd. Tapping-1 +M2.6x8 2
DY5 102 3 1302 61011 Screw, Pan Hd. Tapping-1 +M2.6x10 3
DY6 102 3 1703 00811 Screw, Bind Hd. Tapping-1 +M3.0x8 1
NOTES:
1.
Parts
order
must
contain
Model
Number,
Part
Number
and
Description.
2.
Ordering
quantity
of
screws
and
resistors
must
be
multiple
of
10
pcs.
—10—