SONY ST-ES77
Service Manual

SECTION 2 DISASSEMBLY

SECTION 3 ELECTRICAL ADJUSTMENTS
Precautions in Repairing If the front unit fails, it is difficult to repair the inner circuits, so replace the entire front end unit. The FM TUNED level must be adjusted after the AM TUNED level adjustment has completed. AM SECTION
2 case

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

1 two screws (case 3 TP2)

AM Tuning Level Adjustment Setting : BAND switch : MW(AM)

loop antenna AM RF signal generator loop antenna supplied accessories

set 30 % amplitude modulation by 400 Hz signal Carrier frequency : 999 kHz (at 9 k step) 1,000 kHz (at 10 k step) Output level : 25 dBµ
5 two screws (BVTP3 � 8)

AM antenna terminal 60 cm field strength dB(µV/m)= RF SSG output level dB (µV/m)�26 dB

3 flat wire (19 core) (CN102)

8 main board

1 two screws (case 3 TP2)

Procedure: 1. Set loop antenna A so that the loop antenna B input level becomes 55 dBµ/m. 2. Tune the set to 999 kHz or 1,000 kHz. 3. Adjust RV1 so that the TUNED indicator goes on. Adjustment Location : MAIN board. FM SECTION
4 three screws (BVTP3 � 10)

Adjustment Location : [MAIN BOARD] � Component Side �
RV2 FM Tuning Level Adjustment

CN101 FE2

TM1

FM Tuning Level Adjustment Setting : BAND switch : FM
FM RF Stereo signal generator
IC1
set

6 claw

Carrier frequency : 98 MHz Moduration : AUDIO 1kHz,75 kHz FM antenna terminal deviation (100%) (75 � coaxial) Output level : 26 dBµ (17.8 µV)

7 two claws

Procedure: 1. Tune the set to 98 MHz. 3. Adjust RV2 so that the TUNED indicator goes on. Adjustment Location : MAIN board.

CN102

RV1 AM Tuning Level Adjustment

�7�

�8�