SONY STRW550
Service Manual

SECTION 2 TEST MODE
FL DISPLAY/KEY LED TEST MODE
Press the REPEAT, ENTER/NEXT and SURROUND buttons simultaneously. 1. All FL segments and all LEDs turn on. 2. To access the microprocessor information, press the P FILE key. Each pressing of the P FILE key advances the display on the FL tube in the following sequence. STR microprocessor version number HCD microprocessor version number VCD microprocessor version number (VCD model only) Model name Destination 3. To check the encoder, press the MUSIC key. The following display appears on the FL tube. "K 0 J 0 V 0"

SECTION 3 ELECTRICAL ADJUSTMENTS
(AEP, UK, East European, CIS model) Note: As a front-end (FE1) is difficult to repair if faulty, replace it with new one. (East European, CIS model)

AGING MODE
1. CD aging mode To execute the CD aging, set the three discs to the CD tray and set the function to CD. REPEAT, ENTER/NEXT and LOOP buttons simultaneously. The CD aging mode starts and the disc calendar starts blinking. Tape aging mode To execute the tape aging, set the two tapes to the tape A and B drives. Set the function to TAPE. Press the REPEAT, ENTER/ NEXT and LOOP buttons simultaneously. Press the A forward key to start the tape aging mode. "AGING" appears on the display.

Procedure :
1. Set the modulation of FM RF SSG to AUDIO 1 kHz, 10 kHz deviation according to "Connection 1". 2. Tune the set to 69 MHZ. 3. Adjust the RV1702 so that the reading of frequency counter connected to TP1702 becomes within 31.25 kHz ± 0.05 kHz.(VCO adjustment) 4. Then record the reading of the level meter connected to TP1701 5. Set the modulation of FM RF SSG to AUDIO 31.25 kHz, 10 kHz deviation according to "Connection 2". 6. Tune the set to 69 MHz. 7. Set the CT1701 to be mechanical center. 8. Adjust the L1701 so that the reading of the level meter connected to TP1701 become maximum. Then adjust the CT1701 so that the reading of the level meter connected to TP1701 becomes maximum. (SUB CARRIER PEAK Adjustment) 9. Adjust the RV1701 so that the level at the moment becomes 14dB higher value than the level recorded in step 4. (SUB CARRIER LEVEL Adjustment)

FM Polar Adjustment
FM RF SSG 75 � coaxial

AM Section Adjustment
Setting:
loop antenna AM RF SSG set loop antenna (Supplied accessories)

2.

set

FM ANTENNA terminal (75 �)

Connection 1: CD SERVICE MODE
Turn on the main power. Press the REPEAT, ENTER/NEXT and KARAOKE PON/MPX buttons simultaneously. VACS toggles between ON and OFF.
30% amplitude modulation by 400 Hz signal AM ANTENNA terminal (TM1) Field strength dB (µV/m) =SSG output level dB (µV/m) �26 dB. 60 cm

Carrier frequency : 69 MHz Output level Modulation
AF OSC

: 1mV (60dBµ) (at 75 � open) : AUDIO 1 kHZ, 10kHz deviation
FM RF SSG 75 � coaxial set

AM Tuned Level Adjustment VACS LEVEL DISPLAY
Turn on the main power. Press the EDIT, ENTER/NEXT and KARAOKE PON/MPX buttons simultaneously. VACS level appears on the display. Band: AM or MW Procedure: 1. 2. 3. Set the output of SSG so that the input level of the set becomes 55 dB. set to 999 kHz. Tune the

Adjustment Location:

[TCB BOARD] (Component Side)
IC41 RV41
Audio 31.25 kHz external modulation terminal

The number after K indicates the number of times that the key is pressed. The key which was pressed in the past, is not counted. The key which is pressed hereafter is counted. Pressing any key increases the number after K. The number after J indicates the number of rotations that the JOG dial is rotated. Turning the JOG dial clockwise increases the number after J. Turning the JOG dial counter-clockwise decreases the number after J. The number after V indicates the number of rotations that the VOLUME dial is rotated. Turning the VOLUME dial clockwise increases the number after V. Turning the VOLUME dial counterclockwise decreases the number after V. To exit this mode, perform the "Cold Reset" (reset clearing memory) as described below.

CD SHIP MODE
Turn on the main power. Press the PLAY MODE and POWER buttons simultaneously. The main power is turned off and LOCK appears on the display.

Adjust RV41 to the point (moment) when the TUNED indicator will change from going off to going on. Adjustment Location : TCB board

FM ANTENNA terminal (75 �)

FM Section Adjustment
Note: This adjustment should be performed after the AM Tuned Level Adjustment due to the same adjustment element. Setting:
FM RF stereo signal generator 75 � coaxial

RV42 TM1

Connection 2:
Carrier frequency : 69 MHz Output level Modulation
FE1

TUNER STEP CHANGE
Turn on the main power. Set the function to TUNER. Select MW band from the present tuning. Turn off the main power. Press the ENTER/NEXT and POWER buttons simultaneously. The main power is turned on and the changed step appears on the display.

: 1mV (60 dBµ) (at 75 � open) : AUDIO 31.25 kHZ, 10 kHz deviation (EXTERNAL MODULATION)

Adjustment Location : (East European, CIS model)

[TCB BOARD] (Component Side)
set Carrier frequency : 98 MHz Modulation : AUDIO 1 kH, 75 kHz deviation (100%) FM ANTENNA terminal (TM1) (75 � open)

GENERAL TEST MODE (INCLUDING AMPLIFIER AND TUNER)
Press the REPEAT, ENTER/NEXT and CLOCK TIMER SET buttons simultaneously while the main power is on. 1. Sound volume display segment starts blinking. 2. The tuning enters the PRESET mode. 3. Rotating the VOLUME control clockwise increases the volume level to maximum. Rotating the VOLUME control counter-clockwise decreases the volume level to minimum. Pressing the MUSIC key decreases the equalizer curve to minimum and "EQ CHECK" appears on the display. Pressing the MOVIE key increases the equalizer curve to maximum. Pressing the GAME key makes the equalizer curve flat. Pressing any of the DBFB, GROOVE or SURROUND key disappears "EQ CHECK" on the display.

MD/VIDEO 1 FUNCTION CHANGE
Press the FUNCTION and POWER buttons simultaneously while the main power is on. When the function is set to VIDEO 1, the function is changed to MD and MD appears on the display. When the function is set to MD, the function is changed to VIDEO 1 and VIDEO 1 appears on the display.

RV41 AM tuned level Adjustment

RV41

TM1

FM Tuned Level Adjustment
Band: FM
FE1 IC41 RV42

RV42 FM tuned level Adjustment

COLD RESET (Reset which clears memory.)
Press the REPEAT, ENTER/NEXT and DISPLAY buttons simultaneously at any time. The system is reset while clearing memory.

Procedure: 1. Supply a 25 dBµ 98 MHz signal from the ANTENNA terminal. 2. Tune the set to 98 MHz. If the TUNED indicator does not light, adjust RV42 to the point (moment) when the TUNED indicator will change from going off to going on. Adjustment Location: TCB board 3.

4.

RV1701, TP1701 Sub carrier level Adjustment
RV1701 LEVEL METER + �

5.

HOT RESET (Reset which does not clear memory.)
Press the REPEAT, ENTER/NEXT and TIMER SELECT buttons simultaneously at any time. The system is reset without clearing memory.

CT1701, L1701, TP1701 Sub carrier peak Adjustment

L1701 (FILTER) TP1701

CT1701

To exit this mode, perform the "Cold Reset" (reset clearing memory) as described below.

FREQUENCY COUNTER

RV1702, TP1702 VCO Adjustment

IC1701 TP1702 (VCO) RV1702

+ �

�5�

�6�

�7�