Onkyo T 450 RDS Service Manual

Page 1

Rei No 3465

ONKYO SERVICE MANUAL

SYNTHESIZED
FM STEREO/AM TUNER

MODEL T-45ORDS

Black model

BUD, BUDN

120V AC, 60Hz '

BUP

230V AC, SOHZ

BUW

lZO/ZZOV AC, 50/60Hz

SAFETY-RELATED 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 .........
Scrvic: procedurcsv
Block diagram .......
Exploded view
PanslisL

Microprocessor COMlCCIlOn diagram ............................................... 6

Microprocessor terminal description.

1C block diagrams and descripiions..
Adjustment procedures ............................................................. ll
Primed circuit board vicws from honom sidc.
Schematic diagram.......m..i.......m.i.

Primed circuit board»paris list ....................................
Packing view .......................................................

ONKYO
IIIIIIII BIIMPIIIIHIIS

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SPECIFICATIONS

FM

Tuning range: European & Worldwide models

87.50 - XOSDOMHZ

(50kHz steps)

USA. & Canadian models

87.90 , 107.90MHZ

(200kHz steps)

Mono: I lt2tIEl'. LOPV. 75 Ohms [HF

0l9ttV 75 Ohms DIN

Staten: l7.2dBf2.IhAV, 75 Ohms IHF

ZOuV 75 Ohms DIN

SOdB quinting sensitivity: Mono: 16.le l.7uV 75 Ohms
Stereo: 36. MM l7uV 75 Ohms

Usable sensitivity:

Capture ratio: 1.543
Image rejection ratio: soap
IF rejection ratio: 9MB
Signal-tavnoise ratio: Morin: 7643 lHF

Stereo: 66113 lHF
Alternate channel atlenuation:
60 dB [HF
60dB DIN (Narrow)
(iSOOItHz. 40kHZ dev)
AM suppression ratio: 50:13
Total Harmonic Distortion: Mono: 0.1% (wide)
Stereo: 0.2% (wide)
30 ~ 1500on (:15 dB)
4MB 2! lkHZ (wide)
awe 8170 - I0,000Hz (wide)
0.75V. 0.5V (USA, models only)
I72 dBf2.0 th, 75 Ohms

Selectivity:

Frequency response:
Stereo separation:

Dulpul voltage:
Muting level:

SERVICE PROCEDURES

1. Safetycheck out
(Only U,S.A. model)
After correcting the original service problemperform
the following safety check before releasing the set to
the customer.
Connect the insulating-resistance tester between the
plug of power suuply cord and chassis.

Specifications: More than 10M!) at 500V

2. Mommy preservation
This unit does not require memory preservation batteries,
A built-in memory power backrup 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 charge the
backrup 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.
0n 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 offi This period is
shorter when the unit is exposed to very high humidity or
used in an area with an extremely humid climate.

3. Voltage Selector (Rear Panel)

W models are equipped with a voltage selector to con-
form with local power supplies. 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 a 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
Models without a voltage selector can only be used in
areas where the power supply is the same as that of the
unit.

AM
Tuning range: U.S.A. & Canadian models:
5304710 kHz (I0 kHz steps)
European models:
522 ilfil I kHz (9 kHz Steps)
Worldwide models:
53l71602 kHz (9 kHz steps)
530-[710 kfll (IO kHz steps)
Usable sensitivity: ZSuV
Image rejection ratio: 40cm
IF "ejection ratio: 4on5
Signal-Ionoise ratio: 40dB

Total [demonic Distortion: (17%
Output voltage: lSDmV

General
Power supply: European models (except U.K,):
AC 230V. 50Hz
USA. & Canadian models:
AC 120V, GOHZ
U.K. & Australian models:
AC 240V, JOHZ
Worldwide models:
AC 120V and 220V
switchable. 50/60Hz
Dimensions (W X H x D): 455 X 90 x 306 mm
l7-I5/l6 X 3-9/16" X lZ-l/IG"
Weight: 3.6 kg. 7A lbsr

Specifications and features are subject to change without notice.

4, Tuning Step Frequency Switch (Rear Panel)
W models are equipped with a switch for the AM (9kHz/
lOkHz) and FM (SOkHz/IOOkHz) bands. The switch
should be set to the proper steps for the radio broadcast
frequencies in your area.

5 . Changing the band step
With the exception of the Worldwide models,a BAND
STEP selector switch is not provided.

FM
MODEL BAND STEP 1765 R763
UD 200kHz-+50kHz Short Remove
UP SOkHz-t200kflz Open Add
AM
MODEL BAND STEP 1748 R757
UD 10kHz->9kHz Short Remove
UP 9kHz->10kHz Open Add
1755 I
R763
13): Q75]
SCAN
R757$ l: 1743
47k
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--I AM
DISPLAY CIRCUIT PC BOARD