SONY SLVED8KR
Manual de Servicio

3-4-2. Normal Audio System Adjustment � Make adjustment in the SP mode, unless otherwise specified. Use a normal VHS cassette for an adjustment tape. � Set AUDIO MONITOR to normal. [Adjustment Sequence] 1. 2. 3. 4. ACE Head Adjustment E-E Output Level Check Frequency Responce Check Overall Level Characteristic and Distortion Factor Check 5. Overall S/N Check 1. ACE Head Adjustment Refer to the service manual of VHS MECHANICAL ADJUSTMENT VI. 2. E-E Output Level Check Purpose: Confirm that the output level against the reference input is within the specification. Mode Signal Measurement point Measurement equipment Specified value E-E L, R: 400 Hz, �7.5 dBs Audio output terminal Audio level meter �7.5 ± 2 dBs

4. Overall Level Characteristic and Distortion Factor Check Purpose: Check the record level, play level, and distortion factor against the reference input. Mode Signal Measurement point Measurement equipment Specified value REC and PB (SP mode) 400 Hz, �7.5 dBs Audio output terminal Audio level meter and distortion factor meter Playback level: �7.5 ± 4 dBs Distortion factor: 4% or less

3-6.

PARTS ARRANGEMENT DIAGRAM FOR ADJUSTMENTS

MA-325 BOARD (Side A)
CN501

1 CN341

4

2 1

CT401

Confirmation Method: 1) Supply an audio signal of 400 Hz, �7.5 dBs simultaneously to both L and R channels of Audio Line Input. 2) Make recording 3) Play back a recorded portion. 4) Confirm that a playback level is �7.5 ± 4 dBs. 5) Confirm that a distortion factor is within 4%. 5. Overall S/N Check Purpose: Confirm that the S/N is within the specification. Mode Signal Measurement point Measurement equipment Specified value REC and PB (SP mode) Short Audio output terminal Audio noise meter �46.0 dBs or less
JS161

Confirmation Method: 1) Simultaneously input a signal of 400 Hz, �7.5 dBs to both L and R channels of Audio Line Input. 2) Confirm that the audio output level is �7.5 ± 2 dBs. 3. Frequency Responce Check Purpose: Confirm that the frequency characteristic is within the specification. Mode Signal Measurement point Measurement equipment Specified value REC and PB (SP mode) 400 Hz, �30.0 dBs 7 kHz, �30.0 dBs Audio output terminal Audio level meter 1 ± 4 dB

Confirmation Method: 1) Connect both L and R channels of audio line input to the GND. 2) Start recording. 3) Play the recorded part to confirm that the noise is below �46.0 dBs.

SR-718 BOARD (Side A)

3-5.
3-5-1.

VIDEO SYSTEM ADJUSTMENT
RV201 6V ADJ

Tape path adjustment must have been completed. Confirmation Method: 1) Supply a signal of 400 Hz, �30.0 dBs to both L and R channels of Audio Line Input. 2) Connect the audio level meter to the Audio Line Output. 3) Adjust the attenuator so that the audio level meter will indicate �30.0 dBs. 4) Make recording in the SP mode. 5) Set an audio line input signal to 7 kHz and make recording. 6) Playback a recorded portion, and measure output levels at 400 Hz and 7 kHz. 7) Confirm that the 7 kHz playback output level within a range of the 400 Hz playback output level 1 ± 4 dB.

VCO Oscillation Frequency Adjustment (MA-325 Board) Purpose: Adjust to set the character position on the screen. Mode Signal Measurement point Measurement equipment Adjusting Element Specified value E-E Color bar Pin @§ of IC401 Oscilloscope (DC mode) CT401 2.75 ± 0.05 V
1

CN201 9

VDD = 5.0V 1H

2.75±0.05V GND = 0V

Fig. 7-3-6.

7-5

7-6 E