Technics SAAX 730 Service Manual

Page 1

ORDER NO. M0990507SCZ

S rvice Manual

AV Control Stereo Receiver *D_ Receiver
SA-AX73O

Colour

(K) . . . Black Type

Area
Suffix for
Model No. Area Colour
(E) Europe
K
(EB) Great Britain ( )
(EG) Germany and Italy

* Manufactured under license from Dolby Laboratories Licensing Corporation.
Dolby" ,the double-D symbol and "PRO LOGIC" are trade marks of
Dolby Laboratories Licensing Corporation.

l Specifications
I AMPLIFIER SECTION

Power output
DIN 1 kHz ( T. H. o. 1%)
20 Fla-20 kHz continuous power output
both channels driven

2 X 100 W (69) Frequency response
PHONO RIAA standard curve(30Hz-15kHz) 2 0.8 dB

2 X 80 W (69) CD, TAPE, DVD, VCR, TV 10 Hz - 40 kHz, :t: 3 dB

Total harmonic distortion

rated power at 20 Hz - 20 kHz 0.05% (69)

input sensitivity and Impedance

PHOND 3 mV / 47 k5]

half power at 1 kHz 0.03% (652) CD, TAPE, DVD, VCR, TV 200 mV / 22 kg
Power output at the Dolby Pro Logic operation SIN at rated power (69)
DIN 1 kHz ( T. H. D. 1%) PHONO 70 dB (IHF, A : BOdB)
Front 2 X 100 W (60) CD, TAPE, DVD, VCR, TV 75 dB (IHF, A : 85118)
Center 100 w (69) Tone controls
Surround 2 X 100 W (69) BASS 50 Hz, +10 to -10 dB
Power bandvildth both channels driven,-3dB 10Hz - 40kHz (69) TREBLE 20 kHz, +10 to ~10 dB
Damping factor 30 (an) Output voltage TAPE REC (OUT), VCR OUT 200 mV
Load impedance Channel balance (250 Hz - 6.3 kHz ) :1 dB
Front Channel separation 55 dB
A or B 4-16 52 Headphones output level and Impedance 430 mV / 83052
A and B 8-16 9 Sub-Woofer frequency response 7 -100 Hz, :3 dB
Center 6-16 5)
Surround 6-16 9
A WARNING

This service information is designed for experienced repair technicians only and is not designed for use by the general public. it does
not containiwarnings or cautions to advise non-technical individuals of potential dangers in attempting to service a product. Products
powered by electricity should be serviced or repaired only by experienced professional technicians. Any attempt to service or repair
the product or products dealt with in this service information by anyone else could result in serious injury or death.

© 1999 Matsushita Electronics (8) Pte. Ltd.
All rights reserved. Unauthorized copying
and distribution is a violation of law.

Technics®

Page 2

SA-AX730

I FM TUNER SECTION
Frequency range 87.5 -- 108.0 MHz
Sensitivity
SIN 30 dB 1.5 11V I 759
SIN 26 dB 13 pV I 759
SIN 20 dB 12 av I 759
IHF uasble sensitivity (IHF 58) 1.5 uV I 750
IHF 46 dB stereo quietlng sensitivity 22 31V I 75:)
Total harmonic distortion
MONO 0.2%
STEREO 0.3%
SIN
MONO 60 dB (73 dB, IHF)
STEREO 56 dB (67 dB, IHF)

Frequency response 20H: - 15 kHz +1 (18, -2 dB
Alternate channel selectivity 2400 kHz 65 dB
Capture ratio 1.5 dB
image rejection at SBMHz 40 dB
IF rejection at 98 MHz 70 dB
Spurious response relectlon at 98MHz 70 :13
AM suppression 50 dB
Stereo separation

1 kHz 40 dB
Carrier leak

19 kHz -30 dB (-35 dB. IHF)

38 kHz -50 dB (-55 dB, lHF)
Channel balance (250 Hz - 6.3 kHz) 1 1.5 dB
Limiting point 1.2 v
I Contents me

- Accessories...................,.......
- Belore Repair & Adjustment I Protection Circuitry
- Caution for AC Mains Lead.
- Front Panel Control
. Basic Operations
- Dolby Pro Logic...
. Making A Recording...
0 Using the Remote Control
. Operations Checks
- Terminal Functions of iCs

I Accessories

Bandwidth
IF amplifier 180 kHz
FM demodulator 1000 kHz
Antenna terminal(s) 75K! (unbalanced)
I AM TUNER SECTION
Frequency range 522 - 1611 kHz ( 9 kHz steps)
530 - 1620 kHz ( 10 kHz steps)
Sensitlvty 20 W, 330 pV/m
Selectivity (at 999 kHz) 55 dB
IF rejection (at 999 kHz) 50 dB
I VIDEO SECTION
Output voltage at 1V input (unbalanced) 1:0.1 Vp-p
Maximum input voltage 1.5 Vp-p
Input/output Impedance 75 Q
I GENERAL
Power consumption 240 W (In standby mode : 3 W)

AC 230 - 240V, 50 HZ
430 X 158 x 324.5 mm
9.7 kg

Power supply
Dimensions (W x H x D)
Weight

Notes :
1. Specifications are subject to change without notice.
Weight and dimensions are approximate.
2. Total harmonic distortion is measured by the digital spectrum
analyzer.

PAGE
17
18
. 19 ~23
24~4o
41 ~48

~ Type illustration of I05 Transistors and Diodes ..
~ Wiring Connection Diagram
. Block Diagram ..
0 Schematic Diagra
' Printed Circuit Board

0 Cabinet Pans Location 49
- Repalcement Parts List 50 ~ 52
0 Resistors & Capacitors 53 ~ 57

0 Packing Materials & Acessories
0 Packaging ..................................

58
58

For United For Others
kingdom only
. Plug for United
Power Simply Cord AM Loop antenna set FM indoor antenna Remote Control Batteries Kingdom only

I Before Repair and Adjustment

Disconnect AC power, discharge Power Supply Capacitors C703, C704, C705 and C706 through a 109 , 5W resistor to ground.
DO NOT SHORT-CIRCUIT DIRECTLY (with a screwdriver blade, for instance), as this may destroy solid state devices.

After repairs are completed, restore power gradually using a variac, to avoid overcurrent.

Current consumption at A0 230~240 V, 50Hz in NO SIGNAL mode should be 240 ~ 330 mA.

I Protection Circuitry

The protection circuitry may have operated if either of the
following conditions are noticed :

- No sound is heard when the power is turned 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 it speaker systems with an impedance lessthan
the indicated rated impedance of the amplifier are used.

if this occurs, follow the procedure outlines below:
1. Turn off the power.
2. Determine the cause of the problem and correct it.
3. Turn on the power once again after one minute.

Note:
When the protection circuitry functions, the unit will not operate
unless the power is first turned off and then on again.

W2_

Page 14

SA-AX]30

Main P.C.B.
(Solder Side)

Power P.C.B.
(Solder Side)

direction of arrow .

I Main Component Replacement Procedures

1. Replacement of the Power IC and
RegulatorTransistor

Step 1
Remove the top cabinet.

Fold the Jolnts. (3 joints)

Cut the joints as shown below. (8 joints)

Locate the nipper to the .
thin portion of the joint. N'PPST /

<9

Bottom cover cut\the joint.

Step 4
Desolder the terminals of Power 10 and
Regulator Transistor.

_14,_

Lilt the Main P.C.B. in the