Onkyo ASV 420 Service Manual

Page 1

Ref N0i3520

ONKYO® SERVICE MANUAL

AUDIO VIDEO CONTROL
AMPLIFIER
MODEL A-SV420

Black and Silver models

BMD, BMDN I2OV AC, 60Hz
BMP 230V AC, SOHZ
BMW 120V or 220V AC. 50/60Hz

SAFETY-RELATED COMPONENT WARNINGI!
COMPONENTS IDENTIFIED BY MARK A ON THE
SCHEMATIC DIAGRAM AND IN THE PARTS LIST ARE
CRITICAL FOR RISK OF FIRE AND ELECTRIC SHOCK.
REPLACE THESE COMPONENTS WITH ONKYO PARTS
WHOSE PART NUMBERS APPEAR AS SHOWN IN THIS
MANUAL

MAKE LEAKAGECURRENT OR RESISTANCE MEA-
SUREMENTS TO DETERMINE THAT EXPOSED PARTS
ARE ACCEPTABLY INSULATED FROM THE SUPPLY
CIRCUIT BEFORE RETURNING THE APPLIANCE TO
THE CUSTOMER

ON KYO®
Alilllfl flflMPIININIS

TABLE OF CONTENTS

Specifications ........................................................................... 2
Service procedures ................................................................... 2
Block diagram . .3
Exploded view .

Paris list .................................................................................... 5

Microprocessor connection diagram. .6

Microprocessor descriptions...

1C block diagrams and description

Primed circuit board view ...................................................... 13
Primed circuit board-pans list
Adjustment procedures ...........
Packing view .......................................................................... 24

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SPECIFICATIONS

AMPLIFIER SECTION
Power Output:

Front LIR channels
120 watts per channel min. RMS. at 8
ohms, both channels driven. from 20 Hz
to 20.000 Hz. with no more than 0.08%
total harmonic distortion

Continuous power output
2 x MO watts at 8 ohms IDIN)

Surround mode and Multi source mode

Front L/R and center channels
75W+75W+7SW (l kHz 0.08% Sohms)
Rear channels (Rear only driven!
25W+25Wt| kHz 0.8 We Sohmst
Remote chimnels
75W+75W(| kHz 0.| % thms)
008% at rated power (FRONT)
60 at 8 ohms (FRONT)

IM Distortion:
Damping Factor:
Input sensitmues and impedance:
Phono: 2.5 mV/SO kohms
CD/Tuner/Tape play/Video in.
150 mV/SO kohms
Output level and Impedance:
Tape rec/Video out: 150 mV/2.2 kotims
Pre out (SUBWOOFER): l V/2.2 kohms

SERVICE PROCEDURES

1. Replacing the fuses

-':D- This symbol located near the fuse indicates that the
fuse used is fast operating type. For continued protection against
fire hazard, replace with same type fuse For fuse rating refer to
the marking adjacent to the symbol

-.:D- Ce symbole indique que le fusible utlise est a rapide.
Pour une protection permanente, n'utiliser que des fusibles de
meme type. Ce damier est indique la qu le present symbol est
appose.

CIRCUIT NO. PART No. DESCRIPTION
F901 252146Y 5A-UL/T-237,Primary
F902 252076 3.15A-TSC,Primary

r903 252075 2t5A-SE-EAK,Primary

F921.F922 252156Y lA-UUT-237

252070 lA-SEEAK (P/W)

NOTE I (D) I 120V model only
(P) I 230V model only
(W) I Worldwide model only

.N

To initialize the unit

This device employs a microprocessor to perform various
functions and operations. If interference generated by an external
power supply, radio wave, or other electrical source results in
accident which causes the specified operations and functions to
operate abnormally.

To perform a result, please follow the procedure below.

.5

A-SV420

Phono Overload.
Frequency Response:

120 mV RMS at l,000 Hz. 0.5% THD.
20 to 30000 Hz, +/-l dB

RlAA Deviation 20 to 20.000 Hzt 44-08 dB

Tone Control BASS +I~IO dB at I00 H2
TREBLE' +/710 dB at 10,000 HI

Signal to Noise Ratio: PHONO: 80 dB (IHF A. 5 mV inputJ
CDflAPE: [00 dB (IHF A)

Muttng: - 0° dB

VIDEO SECTION

Signal sensitivity and

impedance: Input. Output 1 Vprpt 75 ohms

GENERAL

Power Supply: USA & Canadian models

AC] 20 V 60 Hz

European models

AC230 V, 50 Hz

Worldwide models

120 and 220 V switchable, 50/60 Hz
455 x 170 x 389 mm

17-15/16 x6-l 1/16>< 156/16
12 l kg (26.7 lbs)

Dimensions (W x H x D):

Mass:

Specifications and features are subject to change without notice.

1. Press 1nd hot-d down the CD button, then press the POWER
button.

2. Take the power supply cord from the socket while TEST-
is displayed.

3. After clear is displayed, the preset memory and each mode
stored in the memory, such as surround, are initialized Ind
will return to the factory settings.

Safety-check out

(Only U.S.A. model)

After correcting the original service problem, perform the
following safety check before releasing the set to the customer.
Connect the insulating-resistance tester between the plug of power
supply cord and the screw on the back panel.

Specifications: 33 Mohm110% at 500V.

Change of voltage

Worldwide models are equipment with a voltage selector to
conform with local power supplies. This switch is located on the
back panel.

Be sure to set this switch to match the voltage of the power supply
in your area before turning the power switch on.

This switch is set to 220V at the factory. Voltage is changed by
sliding the groove in the switch with the screwdriver to the right
or left. Confirm that the switch has been moved all the way to the
right or left before turning the power switch on.

VOLTAGE
SELECTOR

220V-

l20V~