Yamaha K-1020 User manual

$
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CASSETTE
DECK
K-l
0n
I FRONT PANEL
;
aIJITPORTANTNOTICE
This manualhasbecn
providcd
for the use
of authorized
Yamaha
Retailersandtheirservice
personnel.
It has
beenassumedthat basicservicc
proccdures
inhcrantto the industry,andmore
specifically
Yamaha
Products,arealrcadyknown
and
understood
by the
users,
and
have
thereforc
notbeenrcstatcd.
WARNING: Failureto follow appropriateserviceandsafety
procedures
whcn
servicingthis
product
may resultin personal iniury, dcstructionof expcnsivccomponents
and failure of the
product
to perform asspecificd.
For
thescreasons,weadviscall
Yamaha
product
owners
that all serviccrequiredshouldbe performed by anauthorizcdYamahaRetaileror the
dppointed
rervice
reprerentativc.
IMPORTANT: The prescntation
or salc of this manualto any individual
or firm doesnot constitute
authorization,ccrtification,
recognition
of any applicable
technicalcapabilitites,or
establishaprinciple agentrelationshipof anyform.
Thc data provided is belicvedto be accurateand applicableto the unit/s indicatcdon the covcr.
The
rcscarch,engineering,and scrvice departments
of Yamaha arecontinuallystriving
to improveYamaha
products.
Modifications
are,therefore,
inevitable
andchangesin specificationare
subjectto changewithout
notice
or obliSationto retrofit. Shouldany discrepancyappcarto exist,
please
contactthedistributor's
Servicc
Division.
Staticdischargcscandestroyexperrsivecomponents.Discharge
anystaticelectricity
your
body mayhave
accumulatedby grounding
yourself
to the
ground
bussin theunit (heavy
gauge
black
wires
connectto thisbuss).
Turn the unit OFF duringdisassemblyand parts replacement.Recheck
all work before
youapply power
to th€unit.
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I CONTENTS
TOSERVICEPERSONEL ........1
REARPANELS... .....1
BLOCKDIAGRAM ......2
SPEC|F|CAT|ONS. ......3
INTERNALVIEW. ......3
DISASSEMBLYPROCEDURES. ..... 4-6
MECHANICALADJUSTMENTS. 7-9
ELECTRICALADJUSTMENTS. ....9-11
LSIDATA
TABLES 12
TIMINGCHART .......13
PRINTED
CIRCUIT
BOARD
(Pattern
Side) . . 14
- 17
wtRtNG .. .. .. . 18
fcBLocK ..19-21
SCHEMATICDIAGRAM .....22,23
PARTSLTST. .24-36
SINCEI'87
@YAMAHA
NIPPONGAKKICO.,LTD.HAMAMATSU,
JAPAN
2.5k533
El@PrintedinJapan.
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2.
K-ro2()
I TO SERVICEPER,SONNET
CnticalComponents
I
nformation.
Components having special
characteristics
are marked '
and must be replaced
with partshaving
specifications
equal
to those
originally
installed.
Leakage
CurrentMeasurement
(For l20V ModelOnlv)
When servicehas been completed, it is imperarive
ihat yo,
verify that all exposed conductive surfaces
are properly
insulated
from supply
circuits.
Meter impedance
should be equivalent
to 1
5O0ohm shunreo
by 0.1
5r F
Leakage
current
must not exceed
0.5mA.
Be sureto test
for leakagewith
the AC plug in tjoth polaIrres.
I REAR PANELS
U.S.A.
& Canadian
models
Generalmodel
British
& Australian
models
European
model
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K-|o20
T SPECIFICATIONS
Type 4-track.2-channelstereo Input Sonsitivity Impedance
Li
ne 40 mV/30 k-ohms
Head R & P Heads:Combination,PureSendustwith
triple-laminated
core
Erase
Heads:lon-platingFerrite,Double-gap Output Level/Load Impedance
Line
Head
ohones
Channel
Separation
(31
5O
Hz)
CrossTalk i'125 Hzl
Motors Capstan: DCServo
Motor
Reel: Flattorque DC Motor
Assist:
DC Motor
360 mV/47 k-ohms
3.6 mW/8 ohms
40 dB
60 dB
Wow & Flutter No morethan +0.06%
(W.Peak);
No morethan 0.03%
(W.RMS)
PowerSupplios
U.S.& CanadianModels
EuropeanModel
British& Australian
Models
General
Model
12OV
AC,6OHZ
22OVAC, 50HZ
24OV
AC,5OHZ
11
0
I120 I
220 1240VAC. 50/60H2
Fast
Wind Time About 70 seconds/45
seconds
(High
Speed
winding) (C-6O)
Frequency Response
Normaltape(-2OdB)
Chrome
tape(-2OdB)
Metal
tape
(-20d8)
Power
Consumption 28 watts
20 to 18.O00H2
t 3 dB
20 to 20,000H2
+ 3 dB
20 to 23,000H2
t 3 dB
Dimensions{WxHxD} 435 x 134 x 380 mm
17I la" x 5-1
14"
x 15"
Weight 7.6kg {16 lbs.
12oz.}
Signalto Noise
Ratio
Dolby oft
Dolby B on
Dolby C on
dbx on
Morethan 59 dB
Morethan 67 dB
Morethan 75 dB
More
than 95 dB
Specificationsare subject to changewithout notice.
(u)......
(c)
......U.S.A.model
Canadian
model
Harmonic
Distortion
Normal
tape
Chrome
tape
lvletal
tape
Lessthan 0.5%
Lessthan 0.5%
Less
than 0.8%
(A)..........
Australian
model
(G)..........
Europeanmodel
(B)
...... Britishmodel
(R1..........
General
model
I INTTNNAL
VIEW
O PoWER TRANSFoRMER
U.S.A.
& Canadianmodels:
GA68590
Europeanmodel: GA68600
Australian& Britishmodels:
GA68610
Generalmodel: G468620
€)
powEn
clRcurrBoARD
(1)
@
vnrru
crRcurr
BoARD
(1)
()dbx Circuit Board
@ Ootby Circuir Board
@cnpsreru
MoroR
(D
neelMoroR
@
nssrsrMoroR
Op-COM lC: LM6402G-494
@powEa
crRculr
BoARD
3

K-ro2()
I DISASSEMBLY
PR,OCEDURES
1. Adjustment of mechanismunit and replacementof
head
parts.
a. Remove
the cassette lid.
b. Remove2 screws
O in f ig. 'l and removethe blind
Plate.
c. Remove 4 screws
@ in Fig. 1 and removethe front
pl
ate.
* In this state, the head can be adjustedand its parts
canbe replaced.
Fis.1
d. Remove2 screws
O in Fig.
2 andreplace
the record/
playback
head.
e. Removethe screw @ in f ig. 2 and replacethe erase
head.
f. Removethe E ring @ in f ig.2 and replace
the supply
side
pinch roller.
g. Remove
the E ring @ in f ig.2 and replacethe take-
up side
pinch roller.
h. Bemovethe washer
O in f ig.2 and replace
the idler.
. Hsd wiring diagram
{viewed
from the
u
nderside)
Bemoval
of mechanismunit
Remove 5 screws
@ in f ig. 3 and remove the top
cover.
Remove
the cassette lid.
c. Disconnectconnectors
#1
Fis.4.
Fis 3
through rfi, +7 and #8 in
. CONNECTOR
WIRING
oA, G,B models .R model .U, C models BL
2.
d-
b.
d.R
m
CassetteLid
Voltage R. A, G, A mod.l! otrl
rr)RE lF6frE;'Tfil \
t, BE - 312
1
E: G model-
RE: A, B models
Fig.2

d.
I
:
I
i
i
I
;
i
i
!A
Remove 4 screws
€) in f ig. 5 and pull out
mechanism
unit gradually to the rear. Replacementof capstan motor Removethe mechanismunit.
Remove4 screws
@ in f lg. 6 and remove
the back-
plate.
O WIRING
OF MECHANISM
UNIT
the 3.
a.
b.
Fig.5 r''
/
I
J
A
I
I
I
i
j
{
i
. Srtting flywhsl belt
(viryed trom the rsr)
Fig.6
SensorCircuit Board
Reel Motor - Lavel

^
\A
F
c. Remove3 screws
molor. [) in Fig.7 and replacethe capstan
Fig.7
4. Replacement of reel
motor
a. Removethe mechanism
unit.
b. Remove2 screws
@ in Fig.8 and remove
the blind
Plate.
c. Removethe reelbaseasshown in Fig. 8.
" Note that coil springs
of the supply reel and takeup
reelaredifferent.
Supplyside:Silver
Take-upside:
Green
d. Remove the back
plate (Refer
to Fig. 6.)
e. Remove the washer
@ in f ig. 8 and remove the
flywheel (take-up
side).
K-ro20
Remove 2 screws
@ and nuts @ in Fig. 9 and
removethe reelmotor installation
plate.
Remove 2 screws
@ ln fig.9 and replace
the reel
motor.
ReelMotor lnstallation
Plate
Fig.9
5. Replacement
of assistmotor
a. Removethe top cover.
b. Remove the blind plate.
c. Remove2 screws
@ in f ig. 10and removethe assist
motor installation
plate.
d. Remove2 screws
@ in f ig. 10 and
replacethe
assist
motor.
Assist
Motor
lnstallation
Plate
Assist
Motor
Fis.
l0
s.
6
Capstan
Motor
Pushthe reelbase
to the rear
and remove
the ring.
Fig.
I

K-ro20
I MECHANICALADJUSTMENTS
1. Before adjustment
o Since head magnetization, dust accumulations,
etc.
arelikely to introduce error in the various
character-
istics,
it isvery important that the headsare
properly
demagnetized
and
cleaned.
2. lnstruments
required
. Head
Gauge
(M-300)
o Audio
frequencyoscillator
. Oscilloscope
. Mirror
Cassette
{MC-109C}
a Torquemeter
o Wow/fluttermeter
o D.C.V.M.
(DC
Voltagemeter)
. A.C.V.M.
(AC
Voltagemeter)
{/^r
2-r'1
.^
t
Adlustm€nt
at€m Tape Test Point Instrument
required Mode %H".l:iH:,lAdiustmenti natine I Remarks
1Check clear-
ance between
take-up side
pinch roller
and capstan
shaft.
PAUSE Fig. A More than O.5
2Panch Roller
Timing B
Fig
I STOP lWith head base
I jpushed up,
j icheck timing at
I which pinch
I lrollers on
I isuoolv side and
I itake-up side
] lcontact capstan
]
Take-up side Pinc
]
roller should start
I
rotating first.
I
l
lli timing ot both
lsides is samultane-
]ous or supply side
precedes, adj.ust'
lment rsrequrreo.
I
t--
Height of re-
cord/playback
h€ad and tape
guide
ig.o
A.C.V.M.
Oscilloscope
t\,
ir- ""t*tt"
(MC-109C)
-T"rq*t*
(Cassette type)
Repeat adj
ustment
in steps 3 to 6 and
apply screw lock
parnt upon comp-
letion of adjust-
r9!!.
Adjust by using
spacer as shown in
Fig. H.
f" "Ot.n t.t" "P
torque, read the
center of deflec-
tron.
Headgauge L
(M
3oo) I I
1l
Headgauge I lwithM300
(M-3OO) I lblock placed
I lverticallY on re'
I lcord/Playback
I lhead, adjust so
I lthat M 3OO
I lgurg" and block
i ]oecomes Parallel
I l(Fis.
E)
-n."as"ffi
(M-300) i i
PB
Supply side ]
Head gauge should
oinch rotler I
passthrough smoothlV
height adiust- lwathout i.ts
block con-
ing screw (Fig. Jtacting pinch roller
c) lguide. (Fig. F)
n.i. rtn aa- Eavback output of L
justing screw ]and R is maximum
(Fig. C) jand Phase difference
I lshould be minimum
I I
(Phase difference less
I lthan 60")
r lTape should move in
1 lthe center of erase
lhead smoothlY'
lCapstan (suppty side)
I lshould move smoothlv.
rv"""u,-"
Fr -T- --ffi?,"'c,'
REWtorque, i ]35-559/cm
take up torque 1 i FF, REW torque
and back tensi- I
more than 7oglcm
on torque. Back tension: I Back tenslorl:
lAdjustleaf ]5-1Og/cm
spring (5 steps) ]
i{Fie. t) I
4Reco
rdlpl a
V'
back head tilt
angle
5SupplV side
pinch roller
height
Fig.F
6Azimuth 1OkHz,
-10d8
(MTT-
114)
LINE
OUT
7Check Posr
tion of erase
head and tape
movement.
Check each
9Check FF
and BEW tak€
uP t im€s
AC-512
712,22a
c-60
I I l
Normal; Less than u5
I I seconds
I I High speed: Less than
I I I ssseconds
Check speed ls€mr f'xed varr I3OOO
+.:Hz
whileplaying ar,leresrstorat J -rc
jback 3kHz test the back of the I
tape. lg_apstglt
Motor. I
(Fiq. J)
t0 Tape speed 3kHz,
-10dB
(MTT-
111)
LINE
OUT Wow,/f lutter
meter Frequen
cy counter
PB
Wow/ F
lutter
3ooo
+.,
!uz
I
Lessthan O.O5% ]
Check wow/flutter
(WRMS) while confirming
3kHz frequency
with wow/flutter
meter counter.

-1
l^.
I
I
I
Il'o?lJ"li3l
'";,TlI
clearaoce l6190r.
K-ro2()
Fig.
B
Fig.
c
t-rg. E
Difference
beMeen A .nd B
Less than l/2
*Make sure to reconfirm after sdjustment
Adjust by beoding head base
contscting part of supply side
pinch roller.
'Confirm clearance and t;ming atter
acljustment.
There should
bea clear-
ance between lhe pinch arm and
head base
on both supply and t6ke-
up srdes.
Take-up Side Pinch Roller
-\
a
Tape
Supply Side Pinch Roller
Height Adjust Scrw
Capstan
Fig.A
Fig.
D
Er€g
Head
\ ..'
Hesd Fix Screw
r^ Tilt Angle Adjust Scrw
--
---A:' @
' Be sura to tighten the head fixing scrfl securely,
' Be sureio apply scrw lck painr to each adjusiing
scrry after sdjustment.
,/a\
(t@])
\7
Head Gauge
M.300e
y"'
il I .il||ti----
It | .il|t I
il t ililtl
ll L- .t | "r-_I_----'
[r -_:-J I
l_-----
Head Gauge
M-300
Adjust so that the same
clearance is obtained at
the upper and lwor parts.
E
;;;;;* Take-up
side
Pinch
Floller
Fig.F Fis.
G

K-ro2()
' Usespacer
to adjust the h8sd heighl Fig. HFig.I
Capslsn Moto.
Fig.J
I ELECTRI
CAL ADJUSTMENTS
O PLAYBACK
ADJUSTMENTS
* Makesureto use
a new tape of I
ECstandards
for atest
taDe.
Alignmenttape
Normal TDK AC223 or YAMAHA NR 60
CrO2 TDK AC512 or YAMAHA CR 60
METAL TDK ACl12 or YAMAHA MR 60
o Proceed
with the playback adjustmentsafter having
finished
the mechanical
adjustments.
] (dbx
circuit I I
{dbx
circuit i
I 1 board) 1-____1 I board) I
. RECORDINGADJUSTMENT
. Proceedwith the recording
adiustments
after havingfinished the playback
adjustments.
{
t
uHe8d
Hei0hr
Orivcr
/
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i-t-lFr"yb".ki'^
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-i 36otls--v --
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i I I \toonwo/m/ I I rvteter) I l
F_+ _+ _ __ f__t _ I
I s ietayuacr
rrequency Mrr.3s6u I r-rr.re
oui I ; 6nt i t-f---T;"*;,"*;'"
J i r".oonre
confirmation I {3t80
+70ps1 i 1 1 lshoutd
bewrthin
specifi-
response
conTtrmatton (J tUU
+ /Ups, 1 i lshould
bewtthin speciti-
I ],.I,.r';',,tuo|,,I I i ] lcationinFie'K
a ldbx rc 1 Tpl -rp2 D.C.V.M. 1
Srop 1 vRTOt i 15
t 2mVD.C.
I I (dbx
circuit ] {dbx
circuit
t-Aai-'tf"ntT , " -"t^Tt T..rj:l:jt- ,. . ' M"".u,"-"nt Jnai"tln"',tl *;- *.*,--
["n".n=."";r lL^;F;;* faoa*".AppryarkHz
sine*;-]u"*.tLr-r l*aaE
r"n-*,-i -'-l
Meter OUT signal
from LINE lN so iVR5O4
{R) I
(red}
should I
r 1(+4.5dBl I rLiNE l-Au;it that LINE OUT voltasers I ltisf't. I
r ltno
uott j li-,i"
]fll$,"."", $'J*,i,'-iyJrlirtase
is
I lrisht i
fF;k L"*f oscillator f,ppty" rri. rinu
*u* fvnsor tr-r I ooe,"g-"n, -iwrt"n nllnsrEn
-----l
Meter signal
from LINE lN so 1VR502
(R) i(redl should FADER isdecreasedL l
l(OdB) 1 that LINE OUT voltage i tliStrt. and R segments
i 'is 360mV (-gdBV). L aroundOdBshould
I 1 fade
out almostsimul-
* Use360mV
(-9dBV) for 0dBas
the
standardlevelof
this
unit.
. \')A
9
8ek Teosion (5 iteps)
at Playback mode @
@@
l(OdB) 1 that LINE OUT voltage I llight. and R segments
is
360mV {-gdBV}. ] around OdBshould
' , I L fade
out almostsimur- i
_l _ taneousty. I