Technics SUX 980 D Service Manual

Page 2

980D

I CONTENTS

BEFORE REPAIR ................
PROTECTION CIRCUITRY
ACCESSORY ......................
LOCATION OF CONTROLS
CONNECTIONS ...................
DIGITALIZATlON OF AUDIO SIGNALS
DISASSEMBLY INSTRUCTIONS
SCHEMATIC DIAGRAM .............

I BEFORE REPAIR

TERMINAL GUIDE OF ICS,
TRANSISTORS AND DIODES .
PRINTER CIRCUIT BOARDS
WIRING CONNECTION DIAGRAM
BLOCK DIAGRAM ....................
REPLACEMENT PARTS LIST (ca lne )
EXPLODED VIEW ........................
FUNCTIONS OF IC TERMINALS
REPLACEMENT PARTS LIST....
RESISTORS AND CAPACITORS .

(1)Turn off the power supply. Using a 109, 5w resistor connect both ends of power supply
capacitorsic701.C702.6800uF) in order to discharge the voltage.

(2)Betore turning the power supply on , after completion of repair , slowly apply the primary voltage by using
a power supply voltage controller to make sure that the consumed current at 50Hz/60Hz in N0 SlGNAL mode
should be shown below with respect to supply voltage 110V/127V/220V/240V.

Power supply voltage AC110V AC127V A0220V AC24OV
Consumed current 50Hz 241 ~ 733mA 223 ~ 669mA 122 - 365mA 112 ~ 336mA
Consumed current 60Hz 233 ~ 698mA 217 ~ 650mA 119 ~ 356mA 110 ~ 330mA

I PROTECTION CIRCUITRY

The protection circuitry may have operated it either of the following conditions is noticed:

* No sound is heard when the power is switched ON.
zr Sound stops during a performance.

The function of this circuitry is to prevent circuitry damage it, for example, the positive and negative speaker
connection wires are shorted . or it speaker systems with an impedance less than the indicated rated

impedance of this unit are used.
If this occurs, follow the procedure outlined below:

1.Switch OFF the power.

2.Determine the cause of the problem and correct it.

3.Switch ON the power once again.
Note:

When the protection circuitry functions, the unit will not operate unless the power is first switched OFF and then

ON again.

I ACCESSORY

OAC power supply cord ............................ 1
Contiguratlon 01 AC power supply cord differs accordlng to
area.

SJA173..
SJA183..
SJA168 .

SJA1 88 ..

..For (XL) area only.
or (XB) area only.
or (XA) area only.
.,For(EK) area only.

SFDACOSEOS ....... For (E).(EG),(EF).(EH).(EB) and (Ei) areas.

I LOCATION OF CONTROLS
0Front panel

Audio muting switch/indicator (MUTING)--w
Press this switch when a disc is being changed or to
temporarily reduce the volume level (approx. 1/10).

Speaker selector (SPEAKERS)

This selector is used to select the speaker systems
to be used.

MAIN (-~ 1):

Sound can be heard from the speakers connected to
the MAIN" and "SURROUND" terminals.
REMOTE (1 -)=

Sound can be heard (rpm the speaker systems con»
nected to the REMOTE" terminals.

in this position, sound cannot be heard trom the
speaker systems connected to the SURROUND
terminals.

Power swltch (POWER)

Surround-sound swltch
(SURROUND)

This switch is used to switch the surround sound shoot on and
oil. (The switch itsell will be illuminated.)

Super bass swltch (SUPER BASS)
When this switch is switched ON (the switch itself will be it-
luminated). the ultra-low frequency range can be reinforced.

Volume-level indicator (VOLUME LEVEL)

The volume level is indicated in decibels (dB).

The dB indication numerically shows the attenuation
characteristic of the amplifier; the indication ranges Irom
- -dB" (minimum) to 0 dB" (maximum).

The volume level becomes greater as the indication pro-
ceeds from-76 to -74 to -72 dB.

I

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PM smuMD

sum: as

vow»:

volume balance.

Tone controls (BASSITREBLE)

The bass control is (or the low-Irequency sound
range, and the treble control is for the high-
Irequency sound range.

5 Input selectors/Indicators
(INPUT SELECTOR)
These selectors are used to select the sound source to be
heard. such as a disc, radio broadcasts, etc. The correspond-
ing indicator illuminates during operation to indicate the
selected sound source.

Headphones jack (PHONES) J

fl
5mm '__--;:~G
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we: um we: mm was
Balance control (BALANCE) Volume control
This control is used to adjust left/right (VOLUME)

This control is used to
adjust the volume level.

Sampling frequency indicators

These indicators function to illuminate to indicate the

detection of the sampling frequency 01 the digital signals

input to the DIGITAL INPUT terminals on the rear panel

of this unit. (Illumination occurs when digital signals are

received.)

32 Itsz For digital signals with the sampling frequency of
32 kHz mode

«.1 kHz: CD and others

48 Itsz For digital signals with the sampling lrequency of

48 kHz mode
. enEcouT
Rear panel REC ,E)(T1 Voltage selector
/ 2 [our 7 PLAVBACK For (XA)
I UX and (X5) areas
I /-~ CD REC OUTI T1335: OUT Coolinglan W IDATI
TUNER I NE L , l DIGITALINPUT
f PLAVEACKJ PLAVEACK
. i s PHONO GND CD
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Um i PE W" Li w TT
SELECTOR CONTROL smcpnofigc MAIN SURROUND REMOTE
LTuNEn I TURNTABLE . SPEAKER TERMINAL

Phono input capacitance is about 100 pF.

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