Technics SU 810 Service Manual

Page 2

I CONTENTS

Page Page
BEFORE REPAIR .................................. 2 SCHEMATIC DIAGRAM ...................... 10~12
PROTECTION CIRCUITRY . 2 PRINTED CIRCUIT BOARDS AND
ACCESSORY .............. . 2 WIRING CONNECTION DIAGRAM ............ 13~15
LOCATION OF CONTROLS . . . . . . 3 TERMINAL GUIDE OF ICS,
CONNECTIONS ................. . . 4,5 TRANSISTORS AND DIODES .................... 16
DISASSEMBLY INSTRUCTIONS . . 6~8 REPLACEMENT PARTS LIST . . . 17, 18, 21
BLOCK DIAGRAM .................................. 9 EXPLODED VIEW ............................. 19, 20

I BEFORE REPAIR

(1) Turn off the power supply Using a 100, 5 W resistor connect both ends of power supply capacitors (C705, C706, 6800 uF) 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 Hueo Hz in NO SIGNAL mode should be shown below with
respect to supply voltage 220 V/240 V.

Power supply voltage AC 220 V AC 240 V
Consumed current 50 Hz 60~24O mA 55~220 mA
Consumed current 60 Hz 56~227 mA 52~208 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 penormance.
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 ACCESSORY

OAC power supply cord .................................. 1
Configuration of AC power supply cord differs according to area.

SJA193(1.5 m) .......... For (EB) area only.
SFDACOSEOS (1.5 m) . . . .For others.