Overall S/N Check; Video System Adjustment; Vco Oscillation Frequency Adjustment; Parts Arrangement Diagram For Adjustments - Sony SLV-ED8ME Service Manual

4. Overall Level Characteristic and Distortion Factor
Check
Purpose:
Check the record level, play level, and distortion factor against the
reference input.
Mode REC and PB (SP mode)
Signal 400 Hz, –7.5 dBs
Measurement point Audio output terminal
Measurement equipment Audio level meter and
distortion factor meter
Specified value Playback level: –7.5 ± 3 dBs
Distortion factor: 4% or less
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 ± 3 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 REC and PB (SP mode)
Signal Short
Measurement point Audio output terminal
Measurement equipment Audio noise meter
Specified value –46.0 dBs or less
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.
2-5.

VIDEO SYSTEM ADJUSTMENT

2-5-1.

VCO Oscillation Frequency Adjustment

(MA-325 Board)
Purpose:
Adjust to set the character position on the screen.
Mode E-E
Signal Color bar
Pin @§ of IC401
Measurement point
Measurement equipment Oscilloscope (DC mode)
Adjusting Element CT401
Specified value 2.75 ± 0.05 V
2.75±0.05V
V = 5.0V
DD
GND = 0V
1H
Fig. 7-2-6.
7-5
2-6.

PARTS ARRANGEMENT DIAGRAM FOR ADJUSTMENTS

MA-325 BOARD (Side A)
1
CN341
2
1
JS161
SR-718 BOARD (Side A)
RV201
6V ADJ
1 CN201 9
CN501
4
CT401
7-6 E