ONKYO TXSR302 - Service Manual Immediate Download

TX-SR302

SERVICE MANUAL

AV RECEIVER

Silver model

MODEL

TX-SR302

120V AC, 60Hz

MDD, UDD

Ref. No. 3844

112004

RC-479S

SAFETY-RELATED COMPONENT

WARNING!!

COMPONENTS IDENTIFIED BY MARK

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 LEAKAGE-CURRENT OR RESISTANCE

MEASUREMENTS TO DETERMINE THAT EXPOSED

PARTS ARE ACCEPTABLY INSULATED FROM THE

SUPPLY CIRCUIT BEFORE RETURNING THE

APPLIANCE TO THE CUSTOMER.

TX-SR302

SPECIFICATION

Amplifier Section

General

Video Section

Tuner Section

Specifications and features are subject to change without notice.

Tuning Frequency Range:

530 kHz~1710 kHz

Usable Sensitivity:

30 V

S/N Ratio:

40 dB

THD:

0.70 %

Audio Outputs

Analog Outputs:

TAPE, VIDEO 1

Subwoofer Pre Outputs:

Speaker Outputs:

5 + 2

Phones:

Audio Inputs

Digital Inputs:

1 (Optical), 1 (Coaxial)

Analog Inputs:

DVD (MULTICHANNEL), CD, TAPE,

VIDEO 1, VIDEO 2, VIDEO 3

Multichannel Inputs:

Video Outputs

A/V Output:

MONITOR, VIDEO 1

Video Inputs

A/V Input:

DVD, VIDEO 1, VIDEO 2, VIDEO 3

Power Output

Front L/R:

65 W + 65 W

Center:

65 W

Surround L/R:

65 W + 65 W

, 20 Hz~20 kHz, FTC)

Dynamic Power:

160 W + 160 W (3

, Front)

125 W + 125 W ( 4

, Front)

85 W + 85 W (8

, Front)

THD

(Total Harmonic Distortion):

0.08 % (Power Rated)

Damping Factor:

60 (Front, 1 kHz, 8

)

Input Sensitivity and Impedance:

200 mV/ 47 k

(LINE)

Output Level and Impedance:

200 mV/ 470

(REC OUT)

Frequency Response:

10 Hz~100 kHz/ +1 dB, -3 dB (Direct

mode)

Tone Control:

+12 dB, -12 dB, 50 Hz (BASS)

+12 dB, -12 dB, 20 kHz (TREBLE)

SN Ratio:

100 dB (LINE, IHF-A)

Speaker Impedance:

~16

Power Supply:

AC 120 V, 60 Hz

Power Consumption:

4.2 A

Stand-by Power Consumption:

1.6 W

Dimensions (W x H x D):

435 x 150 x 365 x mm

17 1/8 x 5 7/8 x 14 3/8 inches

Weight:

8.4 kg

18.5 lbs

Input Sensitivity/Output Level and Impedance:

1 Vp-p /75

(Composite)

Tuning Frequency Range:

87.5 MHz~108.0 MHz

Usable Sensitivity:

Stereo

17.2 dBf 2 V (75

IHF)

Mono

11.2 dBf 1 V (75

IHF)

S/N Ratio:

Stereo

70 dB (IHF-A)

Mono

76 dB (IHF-A)

THD:

Stereo

0.3 % (1 kHz)

Mono

0.2 % (1 kHz)

Frequency Response :

30 Hz~ 15 kHz / +1 dB, -1 dB

Stereo Separation:

45 dB (1 kHz )

SERVICE PROCEDURES

TX-SR302

1. Replacing the fuses

2. 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 terminal GND on the back panel.

Specifications: More than 10Mohm at 500V

This symbol located near the fuse indicates that the

fuse used is show operating type, For continued protection against

fire hazard, replace with same type fuse, For fuse rating, refer to

the marking adjacent to the symbol.

Ce symbole indique que le fusible utilise est e lent.

Pour une protection permanente, n'utiliser que des fusibles de meme

type. Ce demier est indique la qu le present symbol est apposre.

3. To initialize the unit

This unit does not require memory preservation batteries.

A built-in memory power backup system preserves the contents of

memory during power failures and even when the power cord is unplugged.

The power cord must be plugged in order to charge the backup system.

The memory preservation period after the unit has been turned off varies

depending on climate and placement of the unit. On average, memory

contents are protected over a period of a few weeks after the time the unit

has been turned off.

This period is shorter when the unit is exposed to a very humid climate.

This device employs a microprocessor to perform various

functions and operations. If interference generated by an external

power supply, radio wave, or other electrical sauce results in accident

which causes the specified operations and functions to operate

abnormally.

To perform a result, please follow the procedure below.

1. Press and the hold down the VIDEO 1 button , then press the

STANDBY/ON button when the unit is Power ON.

2. After " Clear " is displayed, the preset memory and each mode

stored in the memory, are initialized and will return to the

factory settings.

5. Memory Preservation

Main microprocessor Q7008

1. Press and the hold down the DISPLAY button , then press the

STANDBY/ON button when the unit is Power ON.

Version is displayed on FL display only for 3 seconds.

2. Press the STANDBY/ON button to Power Off.

4. How to check version of microprocessor?

Version 04212a

ex.

REF. NO.

F6901

F6901 or

F6902

F6902 or

F901

F901 or

F903

F903 or

DESCRIPTION

8A-UL

8A-T/UL-ST2

8A-UL

8A-T/UL-ST2

6.3A-UL/T-237

6.3A-T/UL-ST2

5A-UL/T-237

5A-T/UL-ST2

PART NO.

252198

252261

252198

252261

252166

252260

252164

252258

REMARKS

OPERATION CHECK-1

DC VOLTAGE DETECTION PROTECTORS

CURRENT DETECTION PROTECTORS

TX-SR302

Test - _

Test - 1-00

FL display

Clear

Disappears

0.5 sec.

FL display

Test - _

Test - 4-00

Test - 4-29

Clear

Disappears

1. Set the unit to test mode " Test-1-00 " .

1-1. Press and the hold down the CD button , then press the STANDBY/ON button when the unit is Power ON.

1-2. Press the DVD button, while the " Test - _ " is shown.

Unit will be in the state of " Test-1-00 ".

2. Apply DC voltage (+1.5 to +3V) to MULTI CHANNEL (FL, FR, SL, SR, C) terminal, each channel.

3. Check that " Protect " is shown.

4. Apply DC voltage (-1.5 to -3V) to MULTI CHANNEL (FL, FR, SL, SR, C) terminal, each channel.

5. Check that " Protect " is shown.

6. Press the STANDBY/ON button.

[NOTE1]

Limit time to apply voltage is 0.5 to 1.0 seconds each channel.

When protection operation does not occur at once, try several times.

[NOTE2]

Don't connect speakers or any load.

Don't short speaker terminals.

[NOTE]

In the state of test mode" Test-4-29 ", the pulse waveform output for checking from speaker terminal automatically.

Therefore, oscillator is unnecessary.

1. Set the unit to test mode " Test-4-29 "

1-1. Press and the hold down the CD button , then press the STANDBY/ON button when the unit is Power ON.

1-2. Press the VIDEO 3 button, while the" Test - _ " is shown.

Unit will be in the state of " Test-4-00 ".

1-3. Repeat and press SPEAKERS B button to the " Test-4-29 " is shown.

2. Connect the lord resister (3 ohms) to the speaker terminals.

3. Check that the" Protect " is not shown, and speaker relays not turn OFF.

4. Check the each speaker terminals.

5. Connect the lord resister (1.5 ohms) to the speaker terminals.

6. Check that the " Protect " is shown, and speaker relays turn OFF immediately.

7. Check the each speaker terminals.

8. Press the STANDBY/ON button.

OPERATION CHECK-2

OUTPUT LEVEL & THERMAL DETECTION

TX-SR302

RL6901

D6904

D6903

RL6902

POWER AMP.

PRI.

SEC1

Low

High

+B1

-B1

T901 MAIN

TRANSFORMER

Low

High

Q6303

THERMAL

SENSOR

R6380

THERMAL

DETECTION

OUTPUT

LEVEL

DETECTION

VOLH/

THPRO

Q7008

MAIN

MICROPROCESSOR

Q6303

SEC1H

SPEAKER

OUT

F6901

F6902

Low-voltage

HIGH

VOLTAGE

MODE

LOW

VOLTAGE

MODE

+/- 49 V

+/- 28.9 V

High-voltage

Regarding the power supply system of this unit.

1. High-voltage mode

Usually, the power supply supplies high voltage to the power amplifier circuit when the relay (RL6901) is turned On.

2. Low-voltage mode

When as follows, a power supply changes to the state of supplying low voltage when the relay (RL6901) in turned Off.

(1) Excessive output signal is continuously outputted from power amplifier.

(2) Temperature of a heat sink over 80 degrees.

1. The loss which power amplifier generates is decreased. As a result, the miniaturization of a heat sink is realized.

2. Corresponds to a safety standard.

May not notice the fuse (F6901, F6902) broken in the case of repair.

Because the power supply is continuing supplying voltage from the High side of SEC1 at high-voltage mode.

When a power supply circuit changes to low voltage mode, amplifier does not operate.

Therefore, it is very important to check operation of this power supply system containing a fuse.

[NOTE]

Don't connect speakers or any load.

Don't short speaker terminals.

(1) Set the unit is Multi channel input state.

(2) Set the master volume into the minimum.

(3) Apply sine wave signal to MULTI CHANNEL INPUT (FL+FR+C+SL) terminals.

(4) Connect an oscilloscope to speaker terminal of FL channel.

(5) Adjust master volume so that a speaker output may become distortion about 5%.

(6) Check that the RL6901 and RL6902 are turned Off after about 5 seconds progress.

And the power supply changes to low-voltage mode.

(7) Adjust the master volume so that output voltage may become half.

(8) Check that the RL6901 and RL6902 are turned On after 2 to 3 minutes.

And the power supply returns to high-voltage mode.