Technics SHAC 300 Schematics

Page 1

ORDER NO. MD970707201

Service Manilal

Digital Surround Processor

eno-

I Specifications

I AUDIO
Output voltage] Impedance
Input Impedance
LINE
COAXIAL
Frequency responce
FRONT UR, CENTER,
SURROUND LIR (LARGE)

2 V (at 0dB)/1kfl

22 kg
759

20 Hz » 20 kHz, 11 dB

Delay time
AC - 3 CENTER 0 - 5 ms
SURROUND LIR 0 - 15 ms
DOLBY PRO LOGIC SURROUND IJR 15-30 ms
Total harmonics distortion
FRONT LIFt (1 kHz, 0 dB, PCM) 0.007%
Dynamic range 90 dB
SIN ( IHF A) 96 dB
I Contents
Page
SAFETY PRECAUTIONS .................................................... 2
OERATION CHECKS AND MAIN COMPONENT REPLACEMENT 2 & 3
TERMINAL FUNCTION OF lC'sl . 3 & 4
SCHEMATIC DIAGRAM ......... 4 ~10

TERMINAL GUIDE 0F ICs TRANSISTORS AND DIODES. 10
PRINTED CIRCUIT BOARD ........................................... 11 ~14

ud-

LOGIC

Processor

SH-ACSOO
Colour

Area lm

(PP) usA. and Canada (K)

* Manufactured under license from Dolby Laboratories
LicensingCorpor'ation.
"Dolby", "AC-3" , "Pro Logic " and the double-D symbol
are trade marks of Dolby Laboratories.

Load impedance More than 10 kn

IGENERAL
Power supply
Power consumption

AC 120 V, 60 HZ

15 W

( In standby condition : 4 W )
430 x 69.4 x 301.4 mm
(165/6"x2"7/64"x1 155/64")

2.6 kg (5.7 lb)

Dimensions (W x H x D)

Weight

Notes:
Specifications are subject to change without notice.
Weight and dimensions are approximate.

WIRING CONNECTION DIAGRAM . 15
CABINET PARTS LOCATION .
REPLACEMENT PARTS LIST.
RESISTORS & CAPACITORS .
PACKAGING .......................

by anyone else could result in serious iniury or death.

1:3. WAR N I NG
This service information is designed for experiense repairtechnicians only and is not designed for use by the general public. It does not contain warnings
or cautions to advise non-technical individuals of potential dangers in attempting to sen/ice a product Products powered by electricity should be serviced
or repaired only by experienced professional tech nicians, Any attempt to service or repai r the product or products dealt with in this service information

Technics®

© 1997 Matsushita Electronics (S) Pte. Ltd
All rights reserved, Unauthorized copying and
distribution is a violation of law.

Page 2

sH-Acsoo

I safety Precautions (This "Safety Precaution is applied only in USA.)

1. Before servicing, unplug the power cord to prevent an electric shock . Antenna\
2. When replacing parts, use only manufacturer's recommended components for safety . em'na' Q l
3. Check the condition of the power cord. Replace if wear or damage is evident . j
4. After servicing ,be sure to restore the lead dress, insulation barriers ,insulation papers ,shields ,etc . EXP?
5. Before returning the serviced equipment to the customer, be sure to make the following insulation a?
resistance test to prevent the customer from being exposed to a shock hazard . - Ohmmeer
Fig, 1
0 Insulation Resistance Test 95'5 = 3 5-2M9

1. Unplug the power cord and short the two prongs of the plug with a jumper wire .

2. Turn on the power switch .

3. Measure the resistance value with ohmmeter between the jumper AC plug and each exposed metal
cabinet part ,such as screwheads, antenna ,control shafts ,handle brackets , etc . Equipment with antenna
terminals should read between 3M0 and 5,2MQ to all exposed parts* .(Fig. 1 ) Equipment without EXPOSed ,
antenna terminals should read approximately infinity to all exposed parts . (Fig. 2 ) "W" /

part
*Note :Some exposed parts may be isolated from the chassis by design. These will read infinity .
4, it the measurement is outside the specified limits ,there is a possibility of a shock hazard .The equipment Fig, 2
should be repaired and rechecked before it is returned to the customer . Resistance = Approx ea

I Operation Checks and Main Component Replacement Procedures

" ATTENTION SERVICER " Some chassis component may have shape edges. Be careful when dissembling and servicing.

1. This section describes procedures for checking the operation of the major printed circuit boards and
replacing the main components.

2. For reassembly after operation checks or replacement, reverse the respective procedures.
Special reassembly procedures are described only when required.

3. Select items from the following index when checks or replacement are required.

0 Contents page
- Checking Procedure for each major P.C.B. 2 ~ 3

I Checking Procedure for Major P.C.B.

1. Checking of the Control , Display and Power Switch P.C.B.

[SNE2129-1]
9)»):- 0 (Black)

6)»)1. 02:30:?qu

Remove the top cabinet.

60 r , . ,
caboose
Gooomk«¢.-»
Step 2
0 X1

Control Panel P.C.B.
(Solder Side)

Display P.C.B.
( Solder Side )

Release the two rear claw

Pwr wihP..B.
and pull out the backpanel Claw 0 e S to C

( Solder Side )