Onkyo T 4038 Service Manual

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T-4038

SERIAL N0. 3226

ONKYO SERVICE MANUAL

SYNTHESIZED
FM STEREO/ AM TUNER

MODEL T-4038

Black model

BUD, BLDN ! 120V AC. 60Hz

SAFETY-RELATED COMPONENT WARNING}! TABLE OF CONTENTS

COMPONENTS IDENTIFIED BY MARK A ON

THE SCHEMATIC DIAGRAM AND IN TIIE PARTS Specifications ----------------------- 2

LIST ARE CRITICAL FOR RISK OF FIRE AND Service procedures --------------------- 2

ELECTRIC SHOCK. REPLACE THESE COMPO Block diagram ------------------------ 3

NENTS WITH ONKYO PARTS WHOSE PART Exploded view ------------------------ 4

NUMBERS APPEAR AS SHOWN IN THIS Pans list ------------------------- 5

MANUAL, Packing View ---------------------- 5
Adjustment procedures --------------- 6

MAKE LEAKAGECURRENT OR RESISTANCE Circuit description ---------------------- a

MEASUREMENTS TO DETERMINE THAT EXPOSED Block diagram of IC -------------------- 10

PARTS ARE ACCEPTABLY INSULATED FROM PC board View/parts list

THE SUPPLY CIRCUIT BEFORE RETURNING Display/Switch ---------------------- 12

THE APPLIANCE TO THE CUSTOMER. Main circuit vie -------------------- 13

Main circuit parts list -------------- ' 17

Schematic diagram -------------------- IS

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SPECIFICATIONS

FM:
Tuning Range:
Usable Sensitivity:

50dB Quieting Sensitivity:

Capture Ratio:

Image Rejection Ratio:
IF Rejection Ratio:
Signal-to-Noise Ratio:

ACA:
AM Suppression Ratio:
Harmonic Distortion:

Frequency Response:
Stereo Separation:

Output voltage:
Muting level:

AM:

Tuning Range:

Usable Sensitivity:
Image Rejection Ratio:
1F Rejection Ratio:
SignalrtorNoise Ratio:
Harmonic Distortion:
Output voltage:
GENERAL:
Dimensions

Weight:

87,5107.9MHZ(200kHZ steps)

Mono: 11.2dBf. 2.0;:V,IHF
Stereo: 17.2dBf. 4,0;1V
Mono: 16,1dBf, 3.5;;V
Stereo: 36.1dBf, 35 [1V
1.5dB

40dB

90dB

Mono: 73dB

Stereo: 66dB

50dB IHF(i400kHz)

50dB

Mono: 0.1%

Stereo: 0.2%

3015,000HZ ilfidB
40dB at lkHz

30dB at 70-10,000H2
500mV

17.2dBf, 4;:V

530r1,620kHz(10k Hz steps)
25;:V

40dB

30dB

40dB

0.8%

150mV

435 X 73 X 265mm
17-1/8" X 2*7/8"><10r7/16"
3.0kg., 6.6lbs.

Specifications and features are subject to change without notice.

SERVICE PROCEDURES

1.Safety-check out
(Only USA. model)

After correcting the original service problemperform
the following safety check before releasing the set to

the customer.

Connect the insulatingrresistance tester between the
plug of power suuply cord and chassis.

Specifications: 3.3Mohm t10% at 500V.

2.Memroy preservation

This unit does not require memory preservation batteries.

A builtrin memory power backup 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
baclrup systemi 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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T-4038