Sony STR K740, STR 840P Service Manual

STR-K740P/K840P

SERVICE MANUAL

Ver 1.0 2002. 02

• STR-K740P/K840P are the tuner and the amplifier section in HT-DDW740/DDW840.

Dolby Laboratories Licensing Corporation. “DOLBY” the double-D symbol ; “AC-3” and “PRO LOGIC” are trademarks of Dolby Laboratories Licensing Corporation.

POWER OUTPUT AND TOTAL HARMONIC DISTORTION:

With 8 ohm loads, both channels driven, from 40 – 20,000 Hz; rated 100 watts (STR-K840P only)/80 watts (STR-K740P only) per channel minimum RMS power, with no more than

0.09 % total harmonic distortion from 250 milliwatts to rated output (Models of area code U only).

Amplifier section

POWER OUTPUT Models of area code U, CA Rated Power Output at Stereo Mode

(8 ohms 40 Hz – 20 kHz, THD 0.09 %) STR-K840P: 100 W + 100 W STR-K740P: 80 W + 80 W

Reference Power Output

(8 ohms 1 kHz, THD 0.7 %) STR-K840P: FRONT

STR-K740P: FRONT

Models of area code CEL,CEK Rated Power Output at Stereo Mode

(8 ohms 1 kHz, THD 0.7 %) STR-K840P: 100 W + 100 W STR-K740P: 80 W + 80 W

Reference Power Output

(8 ohms 1 kHz, THD 0.7 %) STR-K840P: FRONT

STR-K740P: FRONT

CENTER SURR

Photo : STR-K840P (SILVER model)

SPECIFICATIONS

:100 W/ch

: 100 W

: 100 W/ch

: 80 W/ch

: 80 W

: 80 W/ch

: 100 W/ch

: 100 W

: 100 W/ch

: 80 W/ch

: 80 W

: 80 W/ch

Models of area code AR, SP Rated Power Output at Stereo Mode

(8 ohms 1 kHz, THD 0.7 %) STR-K840P: 90 W + 90 W

Reference Power Output

(8 ohms 1 kHz, THD 10 %) STR-K840P: FRONT

Models of other area code Rated Power Output at Stereo Mode

(8 ohms 1 kHz, THD 0.7 %) STR-K840P: 100 W + 100 W STR-K740P: 80 W + 80 W

Reference Power Output

(8 ohms 1 kHz, THD 10 %) STR-K840P: FRONT

STR-K740P: FRONT

1) Depending on the sound field settings and the

2) Measured under the following conditions:

US Model

Canadian Model

AEP Model

UK Model

E Model

: 120 W/ch

CENTER SURR

source, there may be no sound output.

Area code Power requirements

E 240 V AC, 50 Hz SP, CEL, CEK, AR 230 V AC, 50 Hz MX 120 VAC, 60 Hz

: 120 W

: 120 W/ch

: 120 W

: 120 W/ch

: 100 W/ch

: 100 W

: 100 W/ch

— Continued on next page —

FM STEREO FM-AM RECEIVER

9-873-544-01

2002B1600-1

Sony Corporation

Home Audio Company

Published by Sony Engineering Corporation

STR-K740P/K840P

Frequency response

MULTI CH IN3), CD, MD/TAPE, DVD/LD, VIDEO 1, 2

10 Hz – 50 kHz +0.5/–2 dB (with sound field, and tone bypassed)

Inputs (Analog)

MULTI CH IN3), CD, MD/TAPE, DVD/LD, VIDEO 1, 2

Sensitivity: 250 mV Impedance: 50 kilohms

: 96 dB

S/N (A, 250 mV

)

3) HT-DDW840 only

4) INPUT SHORT (with sound field and tone bypassed).

5) Weighted network, input level.

Inputs (Digital)

DVD/LD (Coaxial)

Sensitivity: – Impedance: 75 ohms S/N: 100 dB (A, 20 kHz LPF)

VIDEO 2 (Optical)

Sensitivity: – Impedance: – S/N: 100 dB (A, 20 kHz LPF)

Outputs

MD/TAPE (OUT), VIDEO 1

Voltage: 250 mV Impedance: 10 kilohms

(AUDIO OUT) SUB WOOFER

Voltage: 2 V Impedance: 1 kilohms

Tone

Gain levels: ±6 dB, 1 dB step

FM tuner section

Tuning range 87.5 - 108.0 MHz Antenna terminals 75 ohms, unbalanced

Intermediate Frequency

10.7 MHz

Sensitivity

Mono: 18.3 dBf, 2.2 µV/75 ohms Stereo:

Usable sensitivity 11.2 dBf, 1 µV/75 ohms S/N

38.3 dBf, 22.5 µV/75 ohms

Mono: 76 dB Stereo: 70 dB

Harmonic distortion at 1 kHz

Mono: 0.3% Stereo: 0.5%

Separation 45 dB at 1 kHz Frequency response 30 Hz – 15 kHz,

+0.5/–2 dB

Selectivity 60 dB at 400 kHz

AM tuner section

Tuning range Models of area code U, CA

With 10-kHz tuning scale: 530 – 1710 kHz With 9-kHz tuning scale: 531 – 1710 kHz

Models of area code E, AR, MX

With 10-kHz tuning scale: 530 – 1610 kHz With 9-kHz tuning scale: 531 – 1602 kHz

Models of area code MY, SP, CEL, CEK

With 9-kHz tuning scale: 531 – 1602 kHz

Antenna Loop antenna

Intermediate Frequency

450 kHz

Usable sensitivity 50 dB/m (at 1,000 kHz or

999 kHz)

S/N 54 dB (at 50 mV/m) Harmonic distortion 0.5 % (50 mV/m, 400 Hz)

Selectivity

At 9 kHz: 35 dB At 10 kHz: 40 dB

6) You can change the AM tuning scale to 9 kHz or 10 kHz. After tuning in any AM station, turn off the receiver. Hold down PRESET TUNING + and press . All preset stations will be erased when you change the tuning scale. To reset the scale to 10 kHz (or 9 kHz), repeat the procedure.

Video section

Inputs

Video: 1 Vp-p, 75 ohms

Outputs

Video: 1 Vp-p, 75 ohms

General

Power requirements

Area code Power requirements

U, CA, MX 120 V AC, 60 Hz CEL, CEK 230 V AC, 50/60 Hz MY, SP, AR 220 – 230 V AC, 50/60 Hz E 120/220/240 V AC, 50/60 Hz

Power consumption

Area code Power consumption

U, MX STR-K840P: 210 W

STR-K740P: 180 W

CA STR-K840P: 300 VA

STR-K740P: 260 VA

CEL, CEK, MY, SP, STR-K840P: 180 W E, AR STR-K740P: 155 W

Power consumption (during standby mode)

0.5 W

Dimensions 430 145 298 mm

(16 7/8 5 6/8 11 6/8 inches) including projecting parts and controls

Mass (Approx.) 7.0 kg (15 lb 7 oz)

Design and specifications are subject to change without notice.

• Abbreviation U : US model. CA : Canadian model. CEL : AEP model. CEK : UK model. SP : Singapore model. (Malaysia model included.) MX : Mexican model. MY : Malaysia model. AR : Argentine model.

STR-K740P/K840P

SAFETY CHECK-OUT

After correcting the original service problem, perform the following safety checks before releasing the set to the customer: Check the antenna terminals, metal trim, “metallized” knobs, screws, and all other exposed metal parts for A C leakage. Check leakage as described below.

LEAKAGE

The AC leakage from any exposed metal part to earth ground and from all exposed metal parts to any exposed metal part having a return to chassis, must not exceed 0.5 mA (500 microamperes). Leakage current can be measured by any one of three methods.

1. A commercial leakag e tester, such as the Simpson 229 or RCA WT -540A. F ollow the manufactur ers’ instructions to use these instruments.

2. A battery-operated AC milliammeter. The Data Precision 245 digital multimeter is suitable for this job.

3. Measuring the voltage drop across a resistor by means of a VOM or battery-operated A C voltmeter . The “limit” indication is 0.75 V, so analog meters must have an accurate low-v oltage scale. The Simpson 250 and Sanwa SH-63Trd ar e examples of a passive VOM that is suitable. Nearly all battery operated digital multimeters that have a 2V AC range are suitable. (See Fig. A)

Notes on chip component replacement

• Never reuse a disconnected chip component.

• Notice that the minus side of a tantalum capacitor may be

damaged by heat.

Unleaded solder

Boards requiring use of unleaded solder are printed with the leadfree mark (LF) indicating the solder contains no lead. (Caution: Some printed circuit boards may not come printed with the lead free mark due to their particular size.)

: LEAD FREE MARK

Unleaded solder has the following characteristics.

• Unleaded solder melts at a temperature about 40°C higher than ordinary solder. Ordinary soldering irons can be used but the iron tip has to be applied to the solder joint for a slightly longer time. Soldering irons using a temperature regulator should be set to about 350°C. Caution: The printed pattern (copper foil) may peel away if the heated tip is applied for too long, so be careful!

• Strong viscosity Unleaded solder is more viscous (sticky, less prone to flow) than ordinary solder so use caution not to let solder bridges occur such as on IC pins, etc.

• Usable with ordinary solder It is best to use only unleaded solder but unleaded solder may also be added to ordinary solder.

To Exposed Metal

Parts on Set

0.15 µF

Fig. A. Using an AC voltmeter to check AC leakage.

1.5 kΩ

Earth Ground

Voltmeter (0.75 V)

SAFETY-RELATED COMPONENT WARNING!!

COMPONENTS IDENTIFIED BY MARK 0 OR DOTTED LINE WITH MARK 0 ON THE SCHEMATIC DIAGRAMS AND IN THE PARTS LIST ARE CRITICAL TO SAFE OPERATION. REPLACE THESE COMPONENTS WITH SONY PARTS WHOSE PART NUMBERS APPEAR AS SHOWN IN THIS MANUAL OR IN SUPPLEMENTS PUBLISHED BY SONY.

ATTENTION AU COMPOSANT AYANT RAPPORT

À LA SÉCURITÉ! LES COMPOSANTS IDENTIFÉS PAR UNE MARQUE 0 SUR LES DIAGRAMMES SCHÉMATIQUES ET LA LISTE DES PIÈCES SONT CRITIQUES POUR LA SÉCURITÉ DE FONCTIONNEMENT. NE REMPLACER CES COMPOSANTS QUE PAR DES PIÈSES SONY DONT LES NUMÉROS SONT DONNÉS DANS CE MANUEL OU DANS LES SUPPÉMENTS PUBLIÉS PAR SONY.

STR-K740P/K840P

MODEL IDENTIFICATION

— BACK PANEL —

Parts No.

MODEL PARTS No.

K740P : US 4-238-189-2s K740P : Canadian 4-238-189-3s K740P : Malaysia,Singapore 4-238-189-4s K740P : E 4-238-189-5s K740P : AEP 4-238-189-6s K740P : UK 4-238-189-7s K840P : US 4-238-193-0s K840P : Canadian 4-238-193-1s K840P : Malaysia, Singapore 4-238-193-2s K840P : E 4-238-193-3s K840P : AEP 4-238-193-4s K840P : UK 4-238-193-5s K840P : Argentine 4-238-193-8s K840P : Mexican 4-238-193-9s

TABLE OF CONTENTS

1. GENERAL

·········································································· 5

2. TEST MODE ······································································6

3. DIAGRAMS ········································································ 8

3-1. Circuit Board Location ··················································8 3-2. Block Diagrams – MAIN Section – ···························· 10

– DISPLAY/POWER Section –··································· 11 3-3. Printed Wiring Board – DIGITAL Section –··············· 12 3-4. Schematic Diagram – DIGITAL Section (1/2) –·········13 3-5. Schematic Diagram – DIGITAL Section (2/2) –·········14 3-6. Printed Wiring Board – MAIN Section – ···················· 15 3-7. Schematic Diagram – MAIN Section (1/2) – ··············16 3-8. Schematic Diagram – MAIN Section (2/2) – ··············17 3-9. Printed Wiring Board – DISPLAY Section – ··············18 3-10.Schematic Diagram – DISPLAY Section – ················· 19 3-11.Printed Wiring Board – VIDEO Section – ·················· 20 3-12.Schematic Diagram – VIDEO Section – ·····················20 3-13.Printed Wiring Board – POWER Section –················· 21 3-14.Schematic Diagram – POWER Section – ··················· 22 3-15.IC Block Diagrams ······················································ 23 3-16.IC PIN FUNCTION DESCRIPTIONS ······················· 25

4. EXPLODED VIEWS ······················································ 27

4-1. Front Panel Section ····················································· 27 4-2. Chassis Section-1 ························································ 28 4-3. Chassis Section-2 ························································ 29

5. ELECTRICAL PARTS LIST ·······································30

SECTION 1

GENERAL

STR-K740P/K840P

This section is extracted from instruction manual.

ALPHABETICAL ORDER

0 – 9

2 CH wh (26)

A – D

A.DEC wk (24, 26) AM (Except for models of area

code CEL, CEK) es (31, 32) BASS +/– wg (19, 30, 57) CD ql (22) CINEMA STUDIO EX A, B, C

9 (25) Digital Cinema Sound (indicator)

qs (24) DIMMER ej (23) DISPLAY 2 (23, 34, 52) Display qa (23) DVD/LD wa (22)

E – L

ENTER wl (36) FM (Except for models of area

code CEL, CEK) ed (31, 32) FM/AM (Models of area code

CEL, CEK only) es (31, 32)

FM MODE (Models of area code

CEL, CEK only) ed, (Except for models of area code CEL, CEK)

ef (32) INPUT MODE qg (22) IR (receptor) 4 (39, 46, 52) LEVEL 0 (16, 20, 28, 57)

MASTER VOLUME wd (20, 50) MD/TAPE qj (22) MEMORY eh (31, 33) MENU +/– e; (16, 28, 36, 37, 57) MENU </> ea (16, 28, 36, 37, 57) MODE wj (25, 30, 51) MULTI CHANNEL DECODING

(indicator) (HT-DDW840 only)

7 (22) MULTI CH IN (HT-DDW840

only) qf (22) MUTING wf8 (22, 50)

N – S

NAME (36) PHONES (jack) ek (22, 51) PRESET/PTY SELECT +/–

(Models of area code CEL, CEK

only) 3 (33, 34)

PRESET TUNING +/– (Except

for models of area code CEL, CEK) 3 (33, 54)

PTY (models of area code CEL,

CEK only) ef (34) SET UP 6 (4, 16, 37, 57) SHIFT eg (33) SLEEP (HT-DDW740 only) qf

(37) SURR qd (28, 57)

T – Z

TREBLE +/– qh (30, 57) TUNER ws (22, 32, 33, 36) TUNING +/– 5 (32) VIDEO 1 qk (22) VIDEO 2 w; (22)

BUTTON DESCRIPTIONS

?/1 (power) 1 (4, 15, 20, 21,

30, 31, 54)

• Abbreviation

CEK : UK model. CEL : AEP model.

1 74 523

90qaqsqdqf qg qhqjqkqlw; waws8

–

ek ej eh eg ef ed es ea e; wl wk wj wh wg wf wd

STR-K740P/K840P

SECTION 2

TEST MODE

FACTORY PRESET MODE

* All preset contents are reset to the default setting. * Procedure:

While depressing the VIDEO 1 and the 2CH buttons simultaneously, press the power

button to turn on the main power .

?/1

The message “FACTORY” appears and switch off the set. While depressing the VIDEO 1 and the 2CH buttons simultaneously, press the power

button again. The message

?/1

“FACTORY” appears and the present contents are reset to the default values.

AM CHANNEL STEP 9 KHZ/10 KHZ SELECTION MODE

* Either the 9 kHz step or 10 kHz step can be selected for the AM

channel step.

* Procedure:

Set the FUNCTION to AM. Turn off the main power. While depressing the TUNING+ button or the PRESET+ button, press the power

button to turn on the

?/1

main power. Either the message “9 k STEP” or “10 k STEP” appears. Select the desired step.

* For US/Canadian/E model only

SPEAKER SIZE SELECTION MODE

*Either Normal Speaker or Micro Satellite Speaker can be selected. *Procedure: While depressing the LEVEL button, press the po wer

?/1

button to turn the main power. Either the message “NORM. SP.” or “MICRO SP.” is displayed. Select the desired speaker size.

FLUORESCENT INDICATOR TUBE TEST MODE

* All fluorescent segments are tested. When this test is activated,

all segments turn on at the same time, then each segment turns on one after another.

* Procedure:

While depressing the MD/T APE and the SHIFT b uttons simultaneously, press the power

1. All segments turn on.

SLEEP

SP.OFF

LSLCR

( ( ( L F E ) ) )

SSR

DIGITAL

OPT COAX MULTI CH IN

PRO LOGIC DTS MPEGSTEREO MONORDS MEMORY

MULTI CHANNEL DECODING , Digital Cinema Sound , A.F.D. , MODE , 2CH and SET UP LED turn on.

2. Press the VIDEO button, confirm display.

SLEEP

L F E

PRO LOGIC MPEGSTEREO RDS

COAX

A.F .D. , MODE , LEVEL , SET UP , and Dig ital Cinema Sound LED turn on.

button to turn on the main power .

?/1

dB kHz mft.

MHz

k m

MHz

MUTINGINFONEWSTAEQD.RANGE

MUTINGINFOTAD.RANGE

3. Press the VIDEO button, confirm display

SP.OFF C

( ( ( ) ) )

DIGITAL

OPT MULTI CH IN

DTS MONO MEMORY

NEWSEQ

dB Hz ft.

MULTI CHANNEL DECODING , 2CH , SURR and NAME LED turn on.

4. Press the VIDEO button, All segments turn off.

5. Every pressing of the VIDEO button turns on each segment and LED one after another in the same order. (Not only the VIDEO b utton, but also the other buttons such as DVD/LD , TV/SAT , MD/TAPE , CD , TUNER and AUX can be used.)

SOUND FIELD CLEAR MODE

* The preset sound field is cleared when this mode is activated.

Use this mode before returning the product to clients upon completion of repair.

* Procedure:

While depressing the MODE button, press the power

?/1

button to turn on the main power. The message “SURR. CLR.” appears and initialization is performed.

DEMONSTRATION MODE

* Demonstration is performed. * Procedure :

While depressing the SET UP button, press the power

?/1

button. The message appears and demonstration is performed.

* To finish DEMONSTRATION MODE, press the power

?/1

button while the introduction message appears in the display.

SOFTWARE VERSION DISPLAY MODE

* The software version is displayed. * Procedure:

While depressing the ENTER and the A.F.D buttons simultaneously, press the po wer

button to turn on the main

?/1

power . The model name, destination and the software v ersion are displayed.

KEY CHECK MODE

* Button check * Procedure:

While depressing the VIDEO 1 and the SHIFT buttons simultaneously, press the po wer power. “REST 39” appears. (AEP, UK, model: “RESET 38”) Every pressing of any button other than ?/1 and SPEAKERS counts down the buttons. The b uttons which are already counted once are not counted again. When all buttons are pressed “REST 00” appears. When MASTER VOLUME is rotated in clockwise direction, “VOL MIN”, “VOL 1” to “VOL 48”, “VOL MAX” appear.

button to turn on the main

?/1

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