Panasonic SA-AK78, Service Manual

Page: 2 / 84

Overall frequency reponse (+3, -6
dB at DECK OUT)
NORMAL (TYPE I) 35- Hz - 14 kHz
HIGH (TYPE II) 35- Hz - 14 kHz
S/N 50dB (A weighted)
Wow and flutter 0.18 % (WRMS)
Fast forward and rewind time Approx. 120 seconds with C-60
cassette tape
■
CD Section
Sampling frequency 44.1kHz
Decoding 16 bit linear
Frequency response 20 Hz - 20 kHz (+1, -2 dB)
Wow and flutter Below measurable limit
Digit filter 8 fs
D/A converter MASH (1 bit DAC)
■
General
1 Before Use 2
2 Before Repair and Adjustment 2
3 Protection Circuitry 2
4 Accessories 3
5 Handling Precautions For Traverse Deck 4
6 Precaution of Laser Diode 4
7 Operation Procedures 6
8 Self-Diagnostic Display Function 8
9 Description of Error Code 9
Power supply AC 110V/127V/220V/230-240V,
50/60Hz
Power consumption 188 W
Standby
ECO 0.8 W
NORMAL 12 W
Dimensions (WxHxD) 270 x 330 x 339 mm
Weight 8.8 kg
Notes :
1. Specifications are subject to change without notices.
Weight and dimensions are approximate.
2. Total harmonic distortion is measured by the digital spectrum
analyzer.
■
System: SC-AK78 (GC) Music Center : SA-AK78 (GC)
Front Speaker : SB-AK78 (GC)
Center Speaker : SB-PC70 (GC)
Surround Speaker : SB-PS70 (GC)
10 CD Test Mode Function 10
11 Measurements and Adjustments 11
12 Terminal Function of IC’s 13
13 Block Diagram 16
14 Schematic Diagram 26
15 Printed Circuit Board 47
16 Wiring Connection Diagram 57
17 Troubleshooting Guide 59
18 Parts Location and Replacement Parts List 60
CONTENTS
Page Page
1 Before Use
Be sure to disconnect the mains cord before adjusting the voltage selector. Use a minus (-) screwdriver to set the voltage selector
(on the rear panel) to the voltage setting for the area in which the unit will be used. (If the power supply in your area is 117V or
120V, set to the “127V” position.) Note that this unit will be seriously damaged if this setting is not made correctly. (There is no
voltage selector for some countries; the correct voltage is already set.)
2 Before Repair and Adjustment
Disconnect AC power, discharge Power Supply Capacitors C566 - C569, C591 through a 10
Ω
, 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 AC 110V, 127V, 220V, 230-240V, 50 Hz in NO SIGNAL mode should be ~620mA, ~590mA, ~330mA
and ~300mA respectively.
3 Protection Circuitry
The protection circuitry may have operated if either of the following conditions are noticed:
2
SA-AK78