Technics SUX 955 Service Manual

Page 2

I CONTENTS
Page
BEFORE REPAIR DESCRIPTION OF FL PANEL ........................... 11
PROTECTION CIRCUITRY . . TERMINAL GUIDE OF IC'S,
ACCESSORY .............. TRANSISTORS AND DIODES ..................... . . 19
LOCATION OF CONTROLS . . . . . PRINTED CIRCUIT BOARDS 9~23
CONNECTIONS ................ .. . 4. 5 WIRING CONNECTION DIAGRAM . .. 24
DISASSEMBLY INSTRUCTIONS , . . . .6~B FUNCTIONS OF IC TERMINALS . . . 25,26
BLOCK DIAGRAM .............. . . . 9, 10 RESISTORS AND CAPACITORS . 27~30
SCHEMATIC DIAGRAM ......................... 1 1 ~18 REPLACEMENT PARTS LIST . . 30~32
EXPLODED VIEW .................................... 33, 34

I BEFORE REPAIR

(1)Turn off the power supply. Using a 100, SW resistor connect both ends ot power supply
capacitors(C701,C702.6800pF) 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 currentat 50Hz/60Hz in NO SIGNAL mode
should be shown below with respect to supply voltage 220V/240V.

Power supply voltage ACZZOV ACZ40V
Consumed current 50H: 122 ~ 365mA 112 - 336mA
Consumed current 60H: 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.
a: Sound stops during a pertormance.
The function of this circuitry is to prevent circuitry damage it, 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

. AC power supply cord ............................ 1
Configuration of AC power supply cord dltters according to
area.
SJA1 BB .......... For (EB) area only.

SFDACOSEOS . .. .For others.