Onkyo T 4670 Service Manual

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SERIAL NO. 3349V

ONKYO SERVICE MANUAL

SYNTHESIZED
FM STEREO/AM TUNER
MODEL T-4670

Silver and Black models

SAFETFRELATED COMPONENT WARNING
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 COMPO
NENTS WITH ONKYO PARTS WHOSE PART
NUMBERS APPEAR AS SHOWN IN THIS
MANUAL.

MAKE LEAKAGECURRENT OR RESISTANCE
MEASUREMENTS TO DETERMINE THAT EXPOSED
PARTS ARE ACCEPTABLY INSULATED FROM
THE SUPPLY CIRCUIT BEFORE RETURNING

THE APPLIANCE TO THE CUSTOMER

TABLE OF CONTENTS

Specifications V.
Service procedur
Block diagram
Exploded View ,
Parts list .........
Microprocessor description
Block diagrams of 1C
Adjustment procedures .
Printed circuit board View

Main circuit ...............

Display/Switches/Remocon/Volume
Schematic diagrm .............
Printed circuit board parts list
Packing View

I ONKYO
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T-4670

SPECIFICATIONS

FM: AM:
Tuning Range: 8750 - 108.00 MHz(50/25kHz Tuning Range: 522 - 1611kI-Iz (9kHz steps)
steps) and/or 88.00 ~ 108.00MHZ Usable Sensitivity: 25;;V
Usable Sensitivity: Mono: 10.3dBf,0.9/,LV, IHF Image Rejection Ratio: 40dB
0.8].LV DIN (75 ohms) IF Rejection Ratio: 40dB
Stereo: 17.2dBf, 2.0uV, IHF Signal-to-Noise Ratio: 40dB

20,1.V DIN (75 ohms) Total Harmonic Distortion: 0.7%
50:18 Quieting Sensitivity: Mono: 16.1dBf, 1.7uV (75 ohms) Output Voltage: 0~300mV
Stereo: 36.1dBI, 17MV (75 ohms) General
Capture Ratio: 1,3dB (Wide) Dimensions (WXHXD): 435x92><366mm
Image Rejection Ratio: 100dB 17-1/8"><3-5/8"><14-7/16
IF Rejection Ratio: 100dB Weight: 4.2kg 9.3Ibs.

Signal-to-Noise Ratio: Mono: 85dB, II-IF

Supplied accessories: 0 AM loop antennaxl

Stereo: 77dB, IHF
Selectivity: 60dB DIN (Narrow)
AM Suppression Ratio: SSdB
Total Harmonic Distortion: Mono: 003% (Wide)
Stereo: 0.07% (Wide)
Frequency Response: 30 - 15,000Hz+0.5 - 1.0dB
Stereo Separation: 45dB at IkHz (Wide)
33dB at 70 - 10,000Hz (Wide)
Output Voltage: 0 - I V
Muting Level: 17.2dBf, 2.0,.LV (750hms)

SERVICE PROCEDURES

1. Safety-check out
After correcting the original service problem, perform the
following safety check before releasing the set to the
customer.
Connect the insulatingresistance tester between the plug
of power supply cord and chassis.

Specifications: more than 10MB.

2. Memory preservation

This unit does not require memory preservation batteries.
A built-in memory power back-up system preserves
contents of the memory during power failures and even
when the unit is unplugged. The unit must be plugged in
and the power switch turned on and off once in order to
change the back-up system. Note that since this is not a
permanent memory, the power switch must be turned on
and off a few times each month to keep the back-up system
operative. The period of time during which memory
contents are preserved after power has last been turned off
varies depending on climate and placement of the unit.
On the average. memory contents are protected over a
period of 3 to 4 weeks (a minimum of 2 weeks) after the
last time power has been turned off. This period is shorter
when. the unit is exposed to very high humidity or used in
an area with an extremely humid climate.

3 FM T-shaped antennaxl

0 Connecting cablexl

0 RI remote control cablexl
0 Remote control transmitter

Specificatlons and features are subeicl to change without
notice.

. Changing the AM band step

When change the band step, refer the table as shown below.

MODEL BAND STEP J777
UD 10kHz-> 9kHz Additional
UG/UQ 9kHz-sIOkHz Eliminated
J777
c:=:R713
0702

DISPLAY PC BOARD