HT-CT550W, STR-CT550WT - Sony Audio Service Manual (repair manual)

2011E05-1

© 

2011.05

•  STR-CT550WT is the amplifi er, HDMI and tuner section in HT-CT550W.
•  All of the units included in the HT-CT550W (SA-WCT550W/SS-CT550W/STR-CT550WT (main unit)/EZW-RT50) 

are required to confi rming operation of the main unit. Check in advance that you have all of the units.

Digital input formats supported by this system 
are as follows.

* It is possible to input these formats only with HDMI 

connection.

U.S. models:
POWER OUTPUT AND TOTAL HARMONIC 
DISTORTION:
(FTC)
Front L + Front R:

With 4 ohms loads, both 
channels driven, from 225 - 
20,000 Hz; rated 50 Watts 
per channel minimum RMS 
power, with no more than 
1 % total harmonic 
distortion from 250 milli 
watts to rated output.

POWER OUTPUT (reference)
Front L/Front R:

134 W (per channel at 
4 ohms, 1 kHz) 

Canadian, AEP, UK and Taiwan models:
POWER OUTPUT (rated)
Front L + Front R: 

70 W + 70 W (at 4 ohms, 
1 kHz, 1 % THD)

POWER OUTPUT (reference) 
Front L/Front R: 

134 W (per channel at 
4 ohms, 1 kHz)

Inputs
LINE IN

Analog

TV IN, SAT/CATV IN

Digital (Optical)

VIDEO IN

Digital (Coaxial)

Dolby Digital

a

Dolby Digital Plus

a*

Dolby TrueHD

a*

DTS

a

DTS 96/24

a

DTS-HD Master 
Audio

a*

DTS-HD High 
Resolution Audio

a*

DTS-HD Low Bit Rate

a*

Linear PCM 2ch 
48 kHz or less

a

Linear PCM Maximum 
7.1ch 192 kHz or less

a*

Connector

HDMI

TM

 connector

Video inputs/outputs

BD/DVD, GAME, SAT/
CATV; 
640 × 480p, 59.94/60 Hz
720 × 480p, 59.94/60 Hz
1280 × 720p, 59.94/60 Hz
1920 × 1080i, 59.94/60 Hz
1920 × 1080p, 59.94/60 Hz
720 × 576p, 50 Hz
1280 × 720p, 50 Hz
1920 × 1080i, 50 Hz
1920 × 1080p, 50 Hz
1280 × 720p, 29.97/30 Hz
1920 × 1080p, 29.97/30 Hz
1280 × 720p, 23.98/24 Hz
1920 × 1080p, 23.98/24 Hz
Deep Color: 30bit/36bit

Video inputs/outputs (3D) BD/DVD, GAME, SAT/

CATV;
1280 × 720p 59.94/60 Hz

Frame packing
Side-by-Side (Half)
Over-Under 
(Top-and-Bottom)

1920 × 1080i 59.94/60 Hz

Frame packing
Side-by-Side (Half)
Over-Under 
(Top-and-Bottom)

1920 × 1080p 59.94/60 Hz

Side-by-Side (Half)
Over-Under 
(Top-and-Bottom)

1280 × 720p 50 Hz

Frame packing
Side-by-Side (Half)
Over-Under 
(Top-and-Bottom)

1920 × 1080i 50 Hz

Frame packing
Side-by-Side (Half)
Over-Under 
(Top-and-Bottom)

1920 × 1080p 50 Hz

Side-by-Side (Half)
Over-Under 
(Top-and-Bottom)

1920 × 1080p 23.98/24 Hz

Frame packing
Side-by-Side (Half)
Over-Under 
(Top-and-Bottom)

This system incorporates Dolby* Digital and the 
DTS** Digital Surround System.

* Manufactured under license from Dolby 

Laboratories.
Dolby, and the double-D symbol are trademarks of 
Dolby Laboratories.

** Manufactured under license under U.S. Patent #’s: 

5,451,942; 5,956,674; 5,974,380; 5,978,762; 
6,226,616; 6,487,535; 7,212,872; 7,333,929; 
7,392,195; 7,272,567 & other U.S. and worldwide 
patents issued & pending. DTS, DTS-HD and the 
Symbol are registered trademarks, & DTS-HD 
Master Audio, and the DTS logos are trademarks of 
DTS, Inc. Product includes software. © DTS, Inc. 
All Rights Reserved.

This system incorporates High-Definition Multimedia 
Interface (HDMI

™

) technology.

HDMI, the HDMI Logo, and High-Definition 
Multimedia Interface are trademarks or registered 
trademarks of HDMI Licensing LLC in the United 
States and other countries.

“BRAVIA” logo is a trademark of Sony Corporation.

“x.v.Colour (x.v.Color)” and “x.v.Colour (x.v.Color)” 
logo are trademarks of Sony Corporation.

“PlayStation

®

” is a registered trademark of Sony 

Computer Entertainment Inc.

1920 × 1080p 29.97/30 Hz

Frame packing
Side-by-Side (Half)
Over-Under 
(Top-and-Bottom)

1280 × 720p 23.98/24 Hz

Frame packing
Side-by-Side (Half)
Over-Under 
(Top-and-Bottom)

1280 × 720p 29.97/30 Hz

Frame packing
Side-by-Side (Half)
Over-Under 
(Top-and-Bottom)

Deep Color: 30bit/36bit

Audio inputs

BD/DVD, GAME, SAT/
CATV: See “Formats 
supported by this system”.

System

PLL quartz-locked digital 
synthesizer

FM tuner section
Tuning range 

87.5 - 108.0 MHz 
US and Canadian models:
(100 kHz step)
AEP, UK and Taiwan models:
(50 kHz step)

(US and Canadian models)
220 V - 240 V AC, 50/60 Hz
(AEP and UK models)
120 V AC, 50/60 Hz
(Taiwan model)

Antenna (aerial)

FM wire antenna (aerial)

Antenna (aerial) terminals 75 ohms, unbalanced

Power requirements

120 V AC, 60 Hz

Power consumption

On: 50 W
Standby mode: 0.3W or less (Control for HDMI 
is off.)

Dimensions (approx.)

270 mm × 60 mm × 
286 mm (10 3/4 in × 2 3/8 
in × 11 3/8 in) (w/h/d)

Mass (approx.)

1.9 kg (4 lb 4 oz)

Design and specifications are subject to change without 
notice.

s Standby power consumption 0.5 W or less.
s Over 85 % power efficiency of amplifier block is 

achieved with the full digital amplifier, S-Master.

  .............................................   3

2-1. Disassembly 

Flow 

...........................................................   4

2-2. Top 

Case..........................................................................   4

2-3.  Front Panel Block ...........................................................   5
2-4.  Top Shield, Fuse (F900) ..................................................   5
2-5. POWER 

Board 

................................................................   6

2-6. HDMI 

Board 

...................................................................   6

2-7. MAIN 

Board 

...................................................................   7

2-8.  DC Fan (M3001) .............................................................   7

TEST  MODE 

 ............................................................  

8

ELECTRICAL  CHECK 

 .........................................   10

5-1.  Block Diagram - HDMI Section - ...................................   11
5-2.  Block Diagram - MAIN Section - ...................................   12
5-3.  Block Diagram - AMP Section - .....................................   13
5-4.  Block Diagram - POWER SUPLLY Section - ................   14
5-5.  Printed Wiring Board - HDMI Board - ...........................   16
5-6.  Schematic Diagram - HDMI Board (1/2) - .....................   17
5-7.  Schematic Diagram - HDMI Board (2/2) - .....................   18
5-8.  Schematic Diagram - MAIN Board (1/7) - .....................   19
5-9.  Schematic Diagram - MAIN Board (2/7) - .....................   20
5-10.  Schematic Diagram - MAIN Board (3/7) - .....................   21
5-11.  Schematic Diagram - MAIN Board (4/7) - .....................   22
5-12.  Schematic Diagram - MAIN Board (5/7) - .....................   23
5-13.  Schematic Diagram - MAIN Board (6/7) - .....................   24
5-14.  Schematic Diagram - MAIN Board (7/7) - .....................   25
5-15. Printed Wiring Board 
 

- MAIN Board (Component Side) - ................................   26

5-16. Printed Wiring Board 
 

- MAIN Board (Conductor Side) - ..................................   27

5-17.  Printed Wiring Board - DISPLAY Board - .....................   28
5-18.  Schematic Diagram - DISPLAY Board - ........................   29
5-19.  Printed Wiring Board - POWER Board - ........................   30
5-20.  Schematic Diagram - POWER Board - ..........................   31

6-1.  Top Case, Front Panel Section ........................................   50
6-2. Chassis 

Section 

...............................................................  51

  ..............................   52

NOTES  ON  CHIP  COMPONENT  REPLACEMENT
• 

Never reuse a disconnected chip component.

• 

Notice that the minus side of a tantalum capacitor may be dam-
aged by heat.

SAFETY  CHECK-OUT
After correcting the original service problem, perform the follow-
ing safety check before releasing the set to the customer:
Check the antenna terminals, metal trim, “metallized” knobs, 
screws, and all other exposed metal parts for AC leakage.
Check leakage as described below.

LEAKAGE  TEST
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 leakage tester, such as the Simpson 229 or RCA 

WT-540A. Follow the manufacturers’ 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 AC voltmeter. The “limit” indication 
is 0.75 V, so analog meters must have an accurate low-voltage 
scale. The Simpson 250 and Sanwa SH-63Trd are examples 
of a passive VOM that is suitable. Nearly all battery operated 
digital multimeters that have a 2 V AC range are suitable. (See 
Fig. A)

0  OR  DOTTED  LINE  

0  ON  THE  SCHEMATIC  DIAGRAMS  AND  IN  

0  SUR  

UNLEADED  SOLDER
Boards requiring use of unleaded solder are printed with the lead-
free 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)

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 fl ow) 
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.

NOTE  THE  IC3500  AND  IC3501  ON  THE  HDMI  BOARD  
REPLACING
IC3500 and IC3501 on the HDMI board cannot exchange with sin-
gle. When these parts are damaged, exchange the entire mounted 
board.

CAPACITOR  ELECTRICAL  DISCHARGE  PROCESSING 
When checking the board, for the electric shock prevention, con-
nect the resistors to both ends of respective capacitor (C935 or 
936) to discharge the capacitor (C935 or 936).

:/2 W

ADVANCE  PREPARATION  WHEN  CONFIRMING  OP-
ERATION
All of the units included in the HT-CT550W (SA-WCT550W/SS-
CT550W/STR-CT550WT (main unit)/EZW-RT50) are required to 
confi rming operation of the main unit. Check in advance that you 
have all of the units.

COMPLETING  SETTINGS  FOR  THE  WIRELESS  
SOUND SYSTEM
Procedure:
1.  Insert the two supplied wireless transceivers (EZW-RT50) into 

the wireless transceiver slot on the rear panel of both the re-
ceiver (STR-CT550WT) and the subwoofer (SA-WCT550W).

 

Rear panel of the receiver (STR-CT550WT)

Wireless transceiver
(EZW-RT50)

Rear panel of the subwoofer (SA-WCT550W)

Wireless transceiver
(EZW-RT50)

2. Press the [

?/1

] (Power) button on the receiver (STR-CT550

WT: main unit). 

3.  If wireless transmission is activated, the LINK/STANDBY in-

dicator on the subwoofer (SA-WCT550W) turns green. 

Note: Refer to the instruction manual for assistance if the LINK/STAND-

BY indicator on the subwoofer (SA-WCT550W) does not turn on.

US and Canadian models

- 120V 60Hz 50W

AEP and UK models

- 220-240V 50/60Hz 50W

Taiwan model

- 120V 50/60Hz 50W

NOTE  OF  REPLACING  THE  IC3100  ON  THE  MAIN  
BOARD  AND  THE  COMPLETE  MAIN  BOARD
When IC3100 on the MAIN board and the complete MAIN board 
are replaced, it is necessary to spread the compound (THERMAL 
COMPOUND G747) (Part No. J-2501-221-A) between the main 
board and the heat sink.
Spread the compound referring to the fi gure below.

•  This set can be disassembled in the order shown below.

Note: Follow the disassembly procedure in the numerical order given.

1 three screws

u 8)

1 three screws

u 8)

3 claw

4 top case

2

Note: When you install the top case, 
 

match the position of two bosses.