Yamaha K1020 Service Manual

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,t^STEREO CASSETTE DECK
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I FRONT PANEL
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aIJITPORTANT NOTICE
This manual has becn providcd for the use of authorized Yamaha Retailers and their service personnel.It has been assumed that basic servicc proccdures inhcrant to the industry, and more specifically YamahaProducts, are alrcady known and understood by the users, and have thereforc not been rcstatcd.
WARNING: Failure to follow appropriate service and safety procedures whcn servicing this productmay result in personal iniury, dcstruction...

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I TO SERVICE PER,SONNET
Cntical Components I nformation.Components having special characteristics are marked and must be replaced with parts having specif ications equalto those originally installed.
Leakage Current Measurement (For l20V Model Onlv)When service has been completed, it is imperarive ihat yo,verify that all exposed conductive surfaces are properlyinsulated from supply circuits.
Meter impedance should be equivalent to 1 5O0 ohm shunreoby 0.1 5r F
Leakage current must not exceed...

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K-|o20
T SPECIFICATIONS
Type4-track. 2-channel stereoI nput Sonsitivity I mpedanceLi ne40 mV/30 k-ohmsHeadR & P Heads: Combination, Pure Sendust withtriple-laminated coreErase Heads: lon-plating Ferrite, Double-gapOutput Level/Load I mpedanceLineHead ohonesChannel Separation (31 5O Hz)Cross Talk i125 Hzl
MotorsCapstan: DC Servo MotorReel: Flat torque DC MotorAssist: DC Motor
360 mV/47 k-ohms3.6 mW/8 ohms40 dB60 dB
Wow & FlutterNo more than +0.06% (W. Peak);No more than 0.03% (W. RMS)
Power SuppliosU.S. &...

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I DISASSEMBLY PR,OCEDURES
1. Adjustment of mechanism unit and replacement of
head parts.
a. Remove the cassette lid.
b. Remove 2 screws O in f ig. l and remove the blind
Plate.
c. Remove 4 screws @ in Fig. 1 and remove the front
pl ate.* In this state, the head can be adjusted and its parts
can be replaced.
Fis. 1
d. Remove 2 screws O in Fig. 2 and replace the record/
playback head.
e. Remove the screw @ in f ig. 2 and replace the erase
head.
f. Remove the E ring @ in f ig. 2 and replace the...

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ii!ARemove 4 screws €) in f ig. 5 and pull out
mechanism unit gradually to the rear.
Replacement of capstan motor
Remove the mechanism unit.
Remove 4 screws @ in f lg. 6 and remove the back-
plate.
O WIRING OF MECHANISM UNIT
the 3.
a.
b.
Fig.5
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. Srtting flywhsl belt(viryed trom the rsr)
Fig.6
Sensor Circuit Board
Reel Motor - Lavel 

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c.Remove 3 screws
molor.
[) in Fig. 7 and replace the capstan
Fig.7
4. Replacement of reel motor
a. Remove the mechanism unit.
b. Remove 2 screws @ in Fig. 8 and remove the blind
Plate.
c. Remove the reel base as shown in Fig. 8.
 Note that coil springs of the supply reel and takeup
reel are different.
Supply side: Silver
Take-up side: 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).
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Remove 2 screws @ and nuts @ in...

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I MECHANICAL ADJUSTMENTS
1. Before adjustment
o Since head magnetization, dust accumulations, etc.
are likely to introduce error in the various character-
istics, it is very important that the heads are properly
demagnetized and cleaned.
2. lnstruments required
. Head Gauge (M-300)
o Audio frequency oscillator
. Oscilloscope
. Mirror Cassette {MC-109C}
a Torque meter
o Wow/flutter meter
o D.C.V.M. (DC Voltagemeter)
. A.C.V.M. (AC Voltagemeter)
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Fig. B
Fig. c
t-rg. E
DifferencebeMeen A .nd BLess than l/2
*Make sure to reconfirm after sdjustment
Adjust by beoding head basecontscting part of supply sidepinch roller.
Confirm clearance and t;ming atteracljustment. There should be a clear-ance between lhe pinch arm andhead base on both supply and t6ke-up srdes.
Take-up Side Pinch Roller
-\
a
Tape
Supply Side Pinch RollerHeight Adjust Scrw
Capstan
Fig. A
Fig. D
Er€gHead
 ..Hesd F ix Screw
r^Tilt...

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 Use spacer to adjust the h8sd heighlFig. HFig. I
Capslsn Moto.
Fig. J
I ELECTRI CAL ADJUSTMENTS
O PLAYBACK ADJUSTMENTS* Make sure to use a new tape of I EC standards for a test
taDe.
Alignment tape
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 adjustments after having finished the mechanical adjustments.
] (dbx circuit I I {dbx circuit iI 1 board) 1-____1 I board) I
. RECORDING ADJUSTMENT
. Proceed with the recording...