Technics SUCH 7 Service Manual

Page 1

ORDER NO. AD9104082C8

Service Manual

Amplifier

Because of unique interconnecting cables,
when a component requires service, send or
bring in the entire system.

I SPECIFICATIONS
(DIN 45 500)

I MAIN AMP. SECTION
Power output Dth kHz THD 1% 60 2x25 w
10kHzTHD 1% BQZXSW
both channel driven at 240 V
Total harmonic distortion

halt power at 1 kHz: Low Amp 0.09% (60)

Headphones output level/impedance 300 mV/aaon
I PFIE AMP. SECTION
Input sensitivity/impedance
PHONO 3 mV/47 k0
MIC 0.7 mV/10 k0
DAT 250 mV/27 k0
SIN (rated power, 60): Low Amp
PHONO 70 dB(lHF. A75 dB)
DAT, co, TAPE a4 dB(|HF. A85 (18)

Graphic equalizer control
80 Hz, 250 Hz, 1 kHZ, 4 kHz, 12.5 kHz

Amplifier
S U-CH7
Color
(K) .......... Black Type
Areas
0833:}, Area Color
(E) Continental Europe.

(EB) Great Britain.

(EG) F.Fi. Germany and Italy.

(K)
Asia, Latin America,
(00) Middle Near East and
Africa.
(GN) Oceania.
System: SC-CH7
I GENERAL
Power consumption 250 W

Power supply
For Great Britain and Oceania AC 50/60 Hz, 230N240 V
For F.R. Germany, Italy and Continental Europe

AC 50/60 HZ, 230 V
For others AC 50/60 HZ, 1 10 V~127 V/220 V~240 V

Dimensions (WXHXD) 215x110><303 mm
(8%2><4/32>< 1 1 5/is")
Weight 4.3 kg (9.3 lb.)
Notes:
1. Total harmonic distortion is measured by the digital spectrum
analyzer.

2. Specifications are subject to change without notice.
3. Weight and dimensions shown are approximate.

Muting -20 dB
Super bass 55 Hz. +4 dB
Output voltage/impedance
DAT REC our 150 mV
System Tuner Amplifier CD Player Cassette Deck Speakers
SC-CH7 ST-CH7L SU-CH7 SL-CH7 RS-CH7 SB-CH7

Technics/ Panasonic

(E) (EB) (EG) (GC) (GN)

Page 2

SU-CH7

I CONTENTS

BEFORE REPAIR .....................................
PROTECTION CIRCUITRY

ACCESSORIES ........................................ 2
HOW TO INSTALL THE SYSTEM .......................... 3
CONNECTIONS .............. .. 4,5
LOCATION OF CONTROLS . . . . .. 6, 7
DISASSEMBLY INSTRUCTIONS .. . 8~1i
DESCRIPTION OF FL PANEL ............................ 12

I BEFORE REPAIR

SCHEMATIC DIAGRAM ........
PRINTED CIRCUIT BOARDS

WIRING CONNECTION DIAGRAM ,.

FUNCTIONS OF IC TERMINALS
BLOCK DIAGRAM
REPLACEMENT PARTS LIST ..
CABINET PARTS LOCATION

PACKING (For System: SC-CH7)

Page
i3~19
20~24
25
.. 26
27~29
. 30~36

. . 37, 38
........................... 39

(1) Turn off the power supply. Using a 100, 5 W resistor connect both ends of power supply capacitors (C703, C704) in order to

discharge the voltage.

(2) Before 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 50 Hz/60 Hz in NO SIGNAL mode should be shown below with

respect to supply voltage 110 V~127 V/220 V~240 V.

Power supply voltage AC 120 V AC 240 V
Consumed current 50 Hz fl 85~255 mA
Consumed current 60 Hz 160~480 mA -

I PROTECTION CIRCUITRY

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

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

The function of this circuitry is to prevent circuitry damage if, for example, the positive and negative speaker connection wires are
shorted", or if 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 ACCESSORIES

OSpeaker cords (2)

OAC power supply cords (1)

for (E, EG) area
for (EB) area
for (GO) area
for (GN) area

IRemote control batteries (2)
(UM-4, AAA, R03)

O FM indoor antenna (1 )

for (E, EB, EG) area
for (GO, GN) area

oAttachment plug (1)
for (EB) area

I Remote control transmitter (t)

for (E, EB, EG) area

for (GO, GN) area