Onkyo T 9890 DSR Service Manual

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Ref. No. 3488

ONKYO SERVICE MANUAL

SYNTHESIZED
FM STEREO/DSR TUNER
MODEL T-9890DSR

BIack model

BUP. BUPV 230V AC. SOHZ

SAFETYRELATED COMPONENT WARNING"
COMPONENTS IDENTIFIED BY MARK [:2 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

Service guide
Block diagram .
Expioded View
Parts list ........

Microprocessor connection diagram .

Microprocessur terminaI descriptions
IC block diagrams and descriptions .............................................. 9
Adjustment procedures ............................................................... 1
Printed circuit board View

Schematic diagram
Printed circuit board-parts list

Packing view ............................................................................. 34

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-9890DSR

SPECIFICATIONS

Tuning Range FM : 87.50 to 108.00MH1 (50l25k1-Iz steps)
DSR(CABLE) : 50 to 855 MHz (lMHz/l00kHz steps)
(SATELLITE) : 950 to 175 MHz (1MHz/100kHz steps) (option)
Usable Sensitivity FM : Mono 10.3 dBt, 0.9 V (75 ohms IHF)
0.8 [JV (75 ohms DIN)
Stereo 17.2 (Bi, 2.0 11V (75 ohms IHF)
20 LIV (75 ohms DIN)
DSR : 63 to 94 dBtLV
50 dB Quieting Sensitivity FM : Mono 16.1 (1131', 1.7 11V (75 ohms)
Stereo 36.1 1131, 17 V (75 ohms)

Capture Ratio FM : 1.3 dB (Wide)
Image Rejection Ratio FM : 100dB
1F Rejection Ratio FM : 100 dB
Signal-to-Noise Ratio FM 2 Mono 85 dB, [HF
Stereo 77 dB, [HF
DSR : 110 dB, IHF
Selectivity FM : 70 dB DIN (+/- 300kI-Iz at 40 kHz Devi.) (Super-Narrow)
AM Supperssion Ratio FM : 55 dB
Total Harmonic FM : Mono 0.03 % (Wide)
Distortion Stereo 0.07 % (Wide)
DSR: 0.007 % (lkHz)
Frequency Response FM : 30 to 15,000 Hz (+05, -1.0 dB)
DSR: 15 to 15,000 Hz (105 dB)
Stereo Separation FM : 45 dB at 1,000 Hz (Wide)
33 dB at 70 to 10,000 Hz (Wide)
DSR : 102 dB
Stereo Threshold FM : 17.2 dBI, 2.0 V (75 ohms)
Qutput FM : 1.0V
DSR: 2.0V

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 insulating-resistance tester between the plug
of power supply cord and chassis.

Specifications: More than 10MQ at 500V.

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.

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PRINTED CIRCUIT BOARD VIEW FROM BOTTOM SIDE

DISPLAY CIRCUIT PC BOARD

POWER SUPPLY CIRCUIT PC BOARD

427' -28-