Technics SU-X955 Service Manual

m CONTENTS
Page Page
BEFORE REPAIR: © tc icic.cetos s dad ccedite ASR oie ayes 2 DESCRIPTION OF FLPANEL ................. cee ee eeeee 11
PROTECTION CIRCUITRY ........... cc cece e ee eee renee 2 TERMINAL GUIDE OF IC’S,
ACCESSORY. dacevtiniak cai tienes on ei ndaridnwnete wer tes 2 TRANSISTORS AND DIODES ............. 0. 0c ce cee 19
LOCATION OF CONTROLS ......... 0... ccc cece eee eens 3 PRINTED CIRCUIT BOARDS ...............000000 00 19~23
CONNECTIONS ......... 2.0.0 cece eee teen eet eeeee 4,5 WIRING CONNECTION DIAGRAM ..................000005 24
DISASSEMBLY INSTRUCTIONS ...............000 cece ues 6~8 FUNCTIONS OF IC TERMINALS ................... 0008 25, 26
BLOCK DIAGRAM ......... 0.0: cece ete ee eee e eee eae 9,10 RESISTORS AND CAPACITORS .................0005 27~30
SCHEMATIC DIAGRAM ............. 000: cece eee eens 11~18 REPLACEMENT PARTSLIST ..............000000 sues 30~32
EXPLODED VIEW... oo. ec ccc ccc cece etree 33, 34
w@ BEFORE REPAIR
(1)Turn off the power supply. Using a 102, 5W resistor connect both ends of power supply
capacitors(C701,C702,6800uF) 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 50Hz/60Hz in NO SIGNAL mode
should be shown below with respect to supply voltage 220V/240V.
AC220V AC240V
122 ~ 365mA | 112 ~ 336mA
119 ~ 356mA | 110 ~ 330mA
m@ 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.
m ACCESSORY
© AC power supply Cord... 6... ee eee 1
Configuration of AC power supply cord differs according to
area.
SJA188 .......... For (EB) area only.
SFDACOSE03_ ....For others.

Technics SU-X955 Specifications

General

Brand	Technics
Model	SU-X955
Category	Amplifier
Language	English