Marantz SD1010 - Page 5

INTRODUCTION
This
service
manual
are
prepared
for
use
by
Authorized
Warranty
Station
and
contains
service
information
for
Marantz
Stereo
Cassette
Deck.
Servicing
information
and
voltage
data
included
in
this
manual
are
intended
for
use
by
the
knowledgeable
and
experienced
technician
only.
All
instructions
should
be
read
carefully.
No
attempt
should
be
made
to
proceed
without
a
good
understanding
of
the
operation
of
the
Cassette
Deck.
The
parts
list
furnishes
information
by
which
replacement
parts
may
be
ordered
from
the
Marantz
Company.
A
simple
description
is
included
for
parts
which
can
be
usually
obtained
through
local
suppliers.
1. P.W. BOARDS
As
can
be
seen
from
the
circuit
diagram,
the
chassis
of
your
Cassette
Deck
consists
of
the
following
units.
Each
unit
mounted
on
a
printed
circuit
board
is
described
within
the
square
enclosed
by
a
bold
dotted
line
on
the
circuit
diagram.
1.
PreAmp
......00.
mounted
on
P.W.
Board
PK1A
2.
MICAmp
.....-.-.
mounted
on
P.W.
Board
PK1B
3.
Rec.
Level.
......-
mounted
on
P.W.
Board
PK1C
4.
Power
LED
......-
mounted
on
P.W.
Board
PK1D
(SD3020)
5.
Speed
Switch......
mounted
on
P.W.
Board
PK1E
(SD3020
&
$D1020)
6.
Skip
Switch
.......
mounted
on
P.W.
Board
PK1F
(SD3020)
7.
Skip
LED
.......-
mounted
on
P.W.
Board
PK1G
(SD3020)
8.
VUMeter
........
mounted
on
P.W.
Board
PK1H
(SD1010
&
SD1020)
9.
Transformer
......-
mounted
on
P.W.
Board
PK
11
10.
REC/PLAY
Switch
..
mounted
on
P.W.
Board
PK1J
2.
TEST
EQUIPMENT
REQUIRED
FOR
SERVICING
For
measuring
or
checking
your
Cassette
Deck,
the
fol-
lowing
instruments
and
materials
are
necessary.
VTVM
Audio
Oscillator
(AF
OSC)
Attenuator (600 {2)
Oscilloscope
Bandpass
Filter
(1
kHz)
IEC A-Curve Filter
Wow
and
Flutter
Meter
Torque
Meter
(Cassette
Type)
Digital
Frequency
Counter
Distortion Meter
Blank
Tapes
(Completely
erased
with
bulk
eraser)
TDK
AC-212
(Normal)
TDK
AC-512
(Special/CrO,)
SONY CS-30 (Fe-Cr)
TDK AC-711 (Metal)
NOTE:
If
any
doubt
is
noted
in
a
measured
value,
use
new
tape.
@ Test Tapes (New Tape)
MTT-111
Wow
and
Flutter,
Tape
Speed
(1-7/8
1.P.S.)
MTT-112
Measurements
of
Output
Level
and
Sig-
nal-to-Noise
Ratio
,
MTT-150
Adjustment
of
Output
Level
MTT-216 Frequency Response (for Normal)
MTT-316
Frequency
Response
(for
Special/CrO2,
Fe-Cr,
Metal)
MTT-121 Cross Talk
MTT-141 Channel Separation
MTT-111SP
Wow
and
Flutter,
Tape
Speed
[(3-3/4
|.P.S.)
$D3020
&
$D1020
Only]
MTT-215M
Head
Azimuth
Adjustment
3. CIRCUIT DESCRIPTION
3.1
TAPE
SPEED
SELECTOR
($D3020
&
SD1020
only)
Tape
speed
is
changed
by
switching
the
motor
speed
to
1,800
rpm
for
1-7/8
ips
or
to
3,600
rpm
for
3-3/4
ips.
In
fast-forward
or
rewind
operation,
however,
the
motor
always
rotates
at
1,800
rpm.
1.
As
shown
in
the
figure
below,
the
motor
rotates
at
1,800
rpm
when
R471
(3
kQ)
and
R472
(8.2
kQ2)
are
shorted
by
transistor
switching
circuit
(S401)
(speed
selector)
or
SO90
(FF/REW).
2.
When
R471
and
R472
are
not
shorted,
the
motor
rotates
at
3,600
rpm.
3.
R471
is
used
for
precisely
adjusting
the
motor
speed
to
3,600
rpm.
4.
To
precisely
adjust
the
motor
speed
to
1,800
rpm,
turn
the
variable
resistor
built-in
the
motor.
NOTE: The motor speed is known by playing back the
test tape MTT-111 and measuring the reproduced
frequency.
Motor speed (rpm) Reproduced frequency {Hz}
1800 3000
6000
1-7/8 1PS
dg Oo
FF/REW
sw
soso S010 TAPE SPEED
ADJ 1-7/8 IPS