Yamaha K-200 User manual

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STEREO CASSETTE DECK
SERVICE MANUAL
■ FRONT PANEL
© Power Switch (POWER)
Eject Button (EJECT)
© Cassette Holder
© Tape Counter/Reset Button (TAPE
COUNTER/RESET)
© Rewind Button ( « )
© Play Button ( > )
© Fast-Forward Button ( W> )
© Stop Button ( □ )
'?• Record-Standby/Pause Button (R EC/PAUSE)
Record-Muting Button (MUTE)
S VU Level Meters (LEVEL)
© Tape Selector Switches (TAPE)
Q Dolby NR Switch (DOLBY NR)
■ J Headphone Jack (PHONES)
^ Microphone Jacks (MIC)
Record Level Control (REC LEVEL)
■ C ONTENTS
Rear Panel.
Names of the Parts.
Disassembly Instructions .
General Adjustments.
Specifications ....
Block Diagram .... ..
Performance Chart for Mechanism Logic...
Printed Circuit Board Pattern-side Layout.
Printed Circuit Board Parts-side Components Layout/Wiring
Schematic Diagram.
. . . .... 1
.. 2
. 3
. 4
. 7
.. . 7
... 8
.. . 10
.. . . . 11
.. . . . 12
SINCE 1887 H YAMUHA
NIPPON GAKKI CO., LTD. HAMAMATSU. JAPAN
Printed in Japan 5.82 erj <&) 2 . 65K

@ Record Input Jacks (LINE IN/REC)
© Playback Output Jacks (LINE OUT/PLAY)
© Power Cord
Australian and British Models
European Model
General Model
1

■ N A MES OF THE PARTS
Top View
© Power transformer
Power cord
@ Main circuit board (2)
Q Main circuit board (1)
© Auto-Shut off solenoid
© Capstan drive motor
© Transport mechanism TM-5A
© Reel drive motor
© Main circuit board (3)
© Switch rods
© VU meters
2
Mat,

K-200
■ DISASSEMBLY INSTRUCTIONS
1. R e m o val of Top Cover
Remove screws (T) and (g) shown in photo 1
(4 screws each right and left) and remove plastic
rivet (5) . The top cover can now be removed.
2. R e m o val of Bottom Cover
Remove screws (T) ~ (§) shown in fig 2, and
remove the bottom cover.
3. R e m o val of Front Panel
a) Remove the top and bottom covers per steps 1,
and 2.
b) Remove screws (T) ~ (§) shown in photo 3, and
remove the front panel.
4. R e m o val of Transport Mechanism
a) Remove the front panel according to step 3.
b) Remove the cassette cover.
c) Unplug all connectors from the mechanism section.
d) Remove screws (T) ~ (?) shown in photo 4, and
remove the transport mechanjsm.
5. Removal of VU Meters
a) Remove the front panel according to step 3.
b) Remove screw (T) shown in photo 5, and remove
the VU meters.
6. Removal of Circuit Board
a) Remove the top and bottom covers and the front
panel according to steps 1, 2 and 3.
b) Remove screws ( 5 ) and (§) shown in photo 5.
c) Remove the plastic rivets (A) and (§) shov/n in
photo 6.
d) Remove screw (T) shown in photo 7, and renove
plastic rivets (A) ~ (C) .
e) After removing all switch rods, the circuit board
can be detached.
3

K
Photo 7
■ GENERAL ADJUSTMENTS
Before Adjustment
1. Set the Dolby NR switch to OFF.
2. As dirty or magnetized heads can deteriorate
measurement results for various parameters, be
sure to perform head demagnetizing and head
cleaning, especially before adjusting frequency
response or head azimuth.
Designated Test Tapes
TEAC.MTT-111 (3 kHz)
TEAC.MTT-212C (160 nWb/m)
or MTT-212 (250 nWb/m)
TEAC.MTT-114 (10 kHz)
TEAC.MTT-216 (3180+ 120 jus)
or MTT-316 (3180 + 70 us)
TDK .SA C-60 (Cr0 2 tape)
TDK .ADC-60 (LH tape)
TDK .MA C-60 (Metal tape)
Playback Adjustments
1. Tape Speed Adjustment
a) Connect a frequency counter to the left or right
channel LINE OUT.
b) Play test tape TEAC MTT-111 (3 kHz) and adjust
the semi-fixed VR in the drive motor base for
a frequency counter reading of 3000 Hz - + 2°oHz.
MTT-HI
c
c
frequency counter
5
P.B
LINE OUT
OODO O
: OOOO 0
- -
2. Playback Level Adjustment
a) Connect a VTVM to LINE OUT.
b) Play test tape TEAC MTT-212C (160 nWb/m)
and adjust VR 101 (left channel) and VR 102
(right channel) for a LINE OUT level reading of
—7±1 dBm (346 mV).
3000 t '5 Hz

K-200
3. Head Azimuth Adjustment
a) Remove the cassette cover.
b) Connect two VTVMs and an oscilloscope to the
left and right channels of LINE OUT.
c) Play test tape TEAC MTT-114 (10 kHz) and turn
the R/P head azimuth adjustment screw so that
the outputs .of both left and right channels are
maximum, equal, and in phase.
d) After adjustment, apply screw lock paint.
4. Playback Frequency Response Check
a) Connect a VTVM to LINE OUT.
b) Play test tape TEAC MTT-216 (3180 + 120
/is : LH) or MTT-316 (3180 + 70/ts : Cr0 2 ) and
confirm that the 10-kHz reading is within ±3 dB
of the 315-Hz reading.
MTT-216
(MTT-316)
LINE OUT
VTVM
Recording Adjustments
1. L e vel Meter Adjustment
a) Connect an audio oscillator to LINE IN and a
VTVM to LINE OUT.
b) Put the deck into the record mode and apply a
1-kHz signal to LINE IN which will cause —7 dBm
(346 mV) at the LINE OUT.
c) Adjust VR 105 (left channel) and VR 106 (right
channel) so that the VU meter pointers read 0 dB
±1.5 dB.
2. R ec ord Level Adjustment
a) Establish the same connections as for level meter
adjustment,above.
b) Put the deck into the record mode and apply a
315-Hz (1-kHz, 333-Hz) signal to LINE IN which
will read -7 dBm (346 mV) at LINE OUT.
c) Use the TDK SA C-60 Cr0 2 tape and record this
signal.
d) Adjust VR 103 (left channel) and VR 104 (right
channel) so that the recorded signal reads -7 dBm
(346 mV) upon playback.
VTVM
OSClLLArOH
0 ©fi
u o ooo oc
p e
\ UNCOUT
* e:
-TaBm t<
3. C h e ck of Recording Bias Current
*Set the DOLBY NR switch to OFF.
a) Connect an audio oscillator to LINE IN and a
VTVM and distortion meter to LINE OUT.
b) Apply a signal to LINE IN which will read —27
dBm (34.6 mV, -20 VU) at LINE OUT.
5

• Cr0 2 Position
a) Use a TDK SA C-60 Cr02 tape and adjust VC 101
(trimmer capacitor, L and R) so that the 14-kHz
record/playback level is within ±3 dB of the 1-kHz
(315-Hz, 333-Hz) record/playback level.
b) At this time, distortion at 315-Hz (1-kHz, 333-Hz),
0 VU must be below 2.5%.
• LH Position
a) Use a TDK AD C-60 (LH) tape and check that the
14-kHz record/playback level is within ±4 dB of
the 315-Hz (1-kHz, 333-Hz) record/playback level.
• METAL Position
a) Use a TDK MA C-60 metal tape and check that the
14-kHz record/playback level is within ±4 dB of
the 315-Hz (1-kHz, 333-Hz) record/playback level.
Location of Adjustment Points
P.B LEVEL
ADJUSTMENT
a
Cr02 BIAS
ADJUSTMENT
(L « ( R )
(®) VR104
//(«)
REC LEVEL
ADJUSTMENT
(L) (R)
! □
METER
ADJUSTMENT

■ SPECIFICATIONS
Track Configuration ....
4 track , 2 channel stereo
Motor .
DC servo motor (capstan)
Heads
Flat torque DC motor
(reel)
. . Hard permalloy rec/play-
Tape Speed.
back head Double-gap
ferrite erase head
. 4.75 cm/sec
Wow and Flutter
WRMS.
. . 0.05%
DIN-45507 .
. . 0.08%
Signal-to-Noise Ratio
(Dolby off, Cr0 2 tape)
. better than 58 dB
(Dolby on, Cr0 2 tape) .
better than 66 dB
Frequency Response
Normal tape (—20 dB) .
40 ~ 15,000 Hz ± 3 dB
Cr0 2 tape (—20 dB)
. . 40 - 15,000 Hz ± 3dB
Metal tape (—20 dB)
40 ~ 15,000 Hz ± 3dB
(0 dB) . .
. . 40 ~ 12,000 Hz ± 3dB
Overall Distortion
Metal tape.
. . less than 1.0% (315 Hz)
Channel Separation .
. . better than 35 dB (1 K Hz)
Crosstalk
. . better than 60 dB (125 Hz)
Erasure rate.
better than 60 dB (400 Hz)
Input Sensitivity/Impedance
Mic . 0 . 3 mV/5K ohms
Line . 6 0 mV/80K ohms
Output Level
Line . 350 mV/2.2K ohms
Phones . 0 . 6mW/8 ohms
Power Supply . A C 120V, 60 Hz (U,C)
AC 220V, 50 JHz (G)
AC 240V, 50 Hz (A,B)
AC 110/1 20/220/240 V,
50/60 Hz (R) ^
Power Consumption ...... 14 W
Dimensions (WxHxD) . . . . 435 x 11 2 x 278 mm
(17-1/8 x 4-13/32 x 11")
Weight . 4 . 5 kg (9.9 ibs)
Specifications subject to change without notice.
TM Dolby Laboratories Licensing Corp.
U : U.S.A. Model
C : Canadian Model
R : General Model
A : Australian Model
B : British Model
G : European Model
■ BLOCK DIAGRAM
7

K-2
IPERFORMANCE CHART FOR MECHANISM LOGIC
FWD
SW104 2
button -»push -
- ► Cl78 charged
- ► TRI 13 —
base of TR113 -
via R202
“ON”
locked by D127
I d i f ferenti- I
ation at C176|
1C 105
pin6 “H"
pin7 “L”
REEL MOTOR
forward drive
HEAD plunger
operation
Dill
con¬
ductive
BRAKE plunger
operation
TRI20I
“ON” I
CAPSTAN MOTOR
drive
voltage to
TR 109,110
Auto Shut-off circuit
stand-by
TR II 5
“OFF”
TRI 07, 108
►
“OFF”
Muting circuit
released
REC button- ► push
SWIOI
SW 101 - I, 3, 5,7,9
SW 101 -2, 4,6,8, 10
L. ch; recording circuit
established
R. ch. recording circuit
established
^ TRII5
TRI07, 108
SWI0M 1
“OFF”
“OFF”
Muting circuit
released
REC INDICATOR
lights
SW 101-12
voltage to
TR117
Tape Selector circuit
operation
Record Protection Tab
present missing
REC IHN
SW
open
closed
1C 105 pin 14
“L”
“H”
1C 105 pin 15
“H”
“ L ”
voltage to
TR 116
Recording Bias circuit
operation
Shut-off
plunger "ON"
REC button lock
disabled

button ■ * push
SW104-3
voltage to
-
TR109.110
Auto Shut*off circuit
stand-by
REW | button -> push
SW 104-1
TRI 13
“ON”
base of TR113
locked by D126
REEL MOTOR reverse
drive
voltage to
-----^
TR109.110
Auto Shut-off circuit
stand-by
FF
(REW)I mode
STOP button -PUSH
SW 104-4
| charge of
Cl79 released
BRAKE plunger
operation
POWER SW
SWI03