DOWNLOAD Sony STR-DH550 / STR-DH750 Service Manual ↓ Size: 5.92 MB | Pages: 80 in PDF or view online for FREE

2 CN951 (5P)

3 CN950 (5P)

6 two screws
 (+BVTP 

u 8)

7 INSULATION board

8 two screws
 (+BVTP 

u 8)

9 two screws
 (+BVTP 

u 8)

6 two screws
 (+BVTP 

u 8)

1 Wire is removed
 

1 Wire is removed
 

8 MAIN board
 section

qa MAIN board
 section

B

B

C

B

C

C

4 one screw
 (+BVTP 

u 8)

5 USB INSULATION
 

4 one screw
 (+BVTP 

u 8)

5 USB INSULATION
 

D

E

D

E

7 two screws
 (+BVTP 

u 8)

0 one screw
 (+BVTP 

u 8)

3  heat sink section

3  heat sink section

4 MAIN board

2 one screw
 (+BVTP 

u 8)

2 one screw
 (+BVTP 

u 8)

2 one screw
 (+BVTP 

u 8)

1  Remove the thirty solders.
 

F

F

F

TUNER  AM  STEP  CHANGE  MODE
(US and Canadian models only)
Either the 9 kHz step or 10 kHz step can be selected for the AM 
channel step.
Procedure:
1.  Press the [

?/1

] button to turn on the main power.

2.  Turn the [INPUT SELECTOR] knob to select the “AM TUNER”.
3.  Press the [?/1] button to turn off the main power.
4.  While pressing the [TUNING MODE] button, press the [?/1] 

button to turn on the main power.

5.  Either the message “10K Step” or “9K Step” appears.
6.  Repeat step (4) to select desired step.

VACUUM  FLOURESCENT  DISPLAY  TEST  MODE
All fl ourescent segments are tested.
When this test is activated, all segments light on at the same time, 
then each segment lights on one after another.
Procedure:
While pressing [SPEAKERS] and [DIMMER] buttons simultane-
ously, press the [

?

/

1

] button to turn on the main power.

1.  ALL segments light on.

2.  Press the [DISPLAY] button to confi rm display as below.

3.  Press the [DISPLAY] button to confi rm display as below.

4.  Press the [DISPLAY] button, all segments light off.

SOUND  FIELD  CLEAR  MODE
The preset sound fi eld is cleared when this mode is activated.
Use this mode before returning the product to clients upon com-
pletion of repair.
Procedure:
1.  While pressing [MUSIC] button, press the [

?/1

] button to 

turn on the main power.

2.  The message “S.F. CLEAR” appears for a moment and 

initialization is performed.

SOFTWARE  VERSION  DISPLAY  MODE
The software version is displayed.
Procedure:
1.  While pressing [A.F.D./2CH] and [PURE DIRECT] buttons 

simultaneously, press the [

?

/

1

] button to turn on the main 

power.

2.  The message “H55 XXX” or “H75 XXX” appears.
 XXX: 

Area 

display

 

Each time the [DISPLAY] button is pressed, “SYS. vX.XX”,

 

“MAIN  vX.XX”, “VIDEO vX.XX”, “OSD vX.XX” and 
“SFLASHvX.XX” appear in this order, and returns to the 
“H55 XXX” or “H75 XXX” display.

 

X.XX: Software version

KEY  CHECK  MODE
Each button can be checked.
Procedure:
1.  While pressing [SPEAKERS] and [PURE DIRECT] buttons 

simultaneously, press the [

?/1

] button to turn on the main 

power.

2.  The message “REST 12” appears.
 

Every pressing of any button other than the [

?/1

] counts 

down the buttons.

3.  The buttons which are already counted once are not counted 

again.

4.  When all buttons are pressed, “REST 00” appears.

SWAP  ALL  MODE
The signal will be swap to all channels so that all speakers will 
have sound output.
Procedure:
1.  While pressing [PURE DIRECT] and [MOVIE] buttons 

simultaneously, press the [

?

/

1

] button to turn on the main 

power.

2.  “SWAP MODE” appears.

INITIALIZE  MODE
All preset contents are cleared when this mode is activated. Use 
this mode before returning the product to clients upon completion 
of repair.

(a) SHIPMENT MODE
Procedure:
1.  While pressing [A.F.D./2CH] and [DIMMER] buttons 

simultaneously, press the [

?

/

1

] button to turn on the main 

power.

2.  The message “CLEARING” appears and the memories are 

reset to the default values.

3.  When done, the message “CLEARED *” appears, the set will 

power off.

(b)  ALL CLEAR INITIALIZE
Procedure:
1.  While pressing [A.F.D./2CH] and [DISPLAY] buttons, press 

the [

?

/

1

] button to turn on the main power.

2.  The message “CLEARING” appears and the memories are 

reset to the default values.

3.  When done, the message “CLEARED *” appears, the set will 

power on.

(c) USER INITIALIZE
Procedure:
1.  Hold the [

?

/

1

] button for 5 seconds.

2.  The message “CLEARING” appears on the display.
3.  After few seconds, “CLEARED *” appears.

PROTECTOR  AUTO  OFF
To disable auto off after protector occur.
Procedure:
1.  While pressing [DISPLAY] and [MOVIE] buttons simultane-

ously, press the [

?

/

1

] button to turn on the main power.

2.  “PROTEVER” appears and switch on the set.

DCAC  TEST  MODE
To test audio output from mic input and speakers.
Procedure:
1.  While pressing [MUSIC] and [DIMMER] buttons simultane-

ously, press the [

?

/

1

] button to turn on the main power.

2.  The message “MIC” appears.
 

MIC: mode that output audio from mic input

HISTORY  MODE
The state that the set is used is memorized.
Procedure:
1.  While pressing [TUNING MODE] and [DISPLAY] buttons si-

multaneously, press the [

?/1

] button to turn on the power and 

“HISTORY” is displayed.

2.  Each time the [ 

M ] [ m ] key of remote commander is pressed,

 

the item is switched in order as follows.

  Protector Count

 C  O  U  N  T   

 

x 

x 

x

 

Total 

Power 

ON 

time  

T x x x x x H x x M

 

Main 

Power 

On

 

M 

x x x x x H x x M

 

Protector 

type

 

P R O T   x x x x 

  Sound Field

 S  N  D   

F  I 

E  L 

D 

 

Function

 

  F  U N C T  I  O N 

  Input Mode

 I 

N  P   

M  O  D  E   

 

Digital 

Select

 

D I  G   S E L  E C T

 Stream

 S  T  R  E  A  M  I 

N  F  O

 Channel Config

 

C 

O N F   x x x x x

 

Headphone

 

H E A  D P H   x  x  x

 

Volume

 

V O L _   x x    

 

Muting

 

M U T  I  N G _  x  x 

 

Bass

 

B 

A 

S 

S 

   x 

x 

x

 

Treble

 

T 

R 

E 

B 

   x 

x 

x

 

Front 

Level

 

F     x x x /  x x x

 

Center 

Level

 

C 

    x x x /  x x x

 

Surround 

Level

 

S     x x x /  x x x

  Surround Back Level
  (Only for STR-DH750)

 

B     x x x /  x x x

  Front Height Level
  (Only for STR-DH750)

 

H 

    x x x /  x x x

 

Temperature

 

T 

E 

M 

P 

_ 

    

 

Total 

Power 

On 

 

T x x x x x H x x M

 

Main 

Power 

On

 

M 

x x x x x H x x M

  Power On Count

 R  E  B  O  X  _ 

 

x 

x 

USB  UPDATE  TEST  MODE
To update micontroller software through USB.
Procedure:
1.  Plug in USB device in power off condition.
2.  While pressing [TUNING MODE] and [PURE DIRECT] 

buttons simultaneously, press the [?/1] button to turn on the 
main power.

3.  The message “UPDATING” appears.
4.  If the updating progress succeeds, the message “COMPLETE” 

appears.

5.  If the updating progress fails, the message “ERROR” appears.

USB  UPDATE  VERSION  MODE
Function that displays the version number of all firmware to 
check whether USB Update Test is necessary or not.
Procedure:
1.  While pressing [TUNING MODE] and [DIMMER] buttons, 

press the [?/1] button to turn on the main power.

2.  The message “VER X.XXX” is displayed. “X.XXX” is 

calculated by adding all fi rmware version.

 Example:
 

(MCU ver. + VIDEO ver. + DSP ver. + OSD ver. + 6)/10 =

 

USB Update version

 

MCU = 1.01, VIDEO = 1.04, DSP = 1.02, OSD = 1.03

 

↓

 

(1.01 + 1.04 + 1.02 + 1.03 + 6)/10 = 1.010

 

1.010 = X.XXX