Technics SUA 800 Service Manual

Page 2

SU-A800

I CONTENTS

eBEFORE REPAIR .........

cFROTECTlON CIRCUITRY. 2
OACCESSORIES ......... 2
OCAUTION FOR AC MAINS LEA 3
eLOCATION OF CONTROLS 4
oCONNECTIONS ........... . ,5~7
ODISASSEMBLY INSTRUCTIONS . 8~11
OHOW TOCHECKTHE MAIN P,C.B. .. 11
oHOW TO REPLACE THE POWER IC .................... 12

I BEFORE REPAIR

Page
OSCHEMATIC DIAGRAM ............................ 13~19
IPRINTED CIRCUIT BOARD DIAGRAM 20~24
OWIRING CONNECTION DIAGRAM ........ 25
OBLOCK DIAGRAM ................ 26
OFUNCTION OF IC TERMINALS ., .......... 27
OREPLACEMENT PARTS LIST ................ 28~30, 33, 34
OCABINET PARTS LOCATION .......................... 31,32
IPACKAGING .......................................... 34

(1) Turn off the power supply. Using a 100. 10 W resistor, connect both ends of power supply capacitors (C701. C702) 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 50/60 H1 in NO SIGNAL mode is mode should be shown below with respect to supply voltage 230 V/240 V.

Power supply voltage AC 230 V AC 240 V

AC110~127V

AC 220~240 V

Consumed current 50 Hz 60~350 mA 50~340 mA

100~550 mA 50~340 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 0N.
'Sound stops during a performance.

The functions 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.

For areas except (E) (EB) (E5) (E0) (GN)

CAUTION:
The AC voltage differs according to the area.

Be sure to set the proper voltage in your area before use.

(For details, please refer to page 6.)

I ACC ESSO R I ES Check the packing canon for these accessories.

' AC power supply cord .............................. 1
(RJAOOBG-K) For (GN) area

(VJA0733) For (EB) area

0 Remote control transmitter (EUR642210) ............... 1

- Batteries ............................................ 2
UM-4 (AAA, R03)
Note: These are available on sale route.

L-I 5 El:
0 Power plug adaptor ................................. 1
(SJP5213-2) For (GO) area

Q5