Sony SLV-789HF - Video Cassette Recorder, Service Manual, Page: 62 / 135

6-2
2-1-5. Input/Output Levels and Impedance
Video input: LINE IN
Input signal: 1 Vp-p, 75 ohms, unbalanced,
sync negative
Video output: LINE OUT
Output signal: 1 Vp-p, 75 ohms, unbalanced,
sync negative
Audio input: LINE IN
Input level: –7.5 dBs
(0 dBs= 0.775 Vrms)
Input impedance: more than 47 kilohms
Audio output:LINE OUT
Standard level: –7.5 dBs at load impedance 47
kilohms
Output impedance: less than 10 kilohms
2-1-6. Adjustment Sequence
The adjustments should be performed in the following sequence.
2-2. POWER SUPPLY CHECK
2-2-1. Output Voltage Check (MA-342 Board)
Mode STANDBY
+30 V Check
Measurement point C627
‘
Specified value 31.0 – 39.0 V
–11 V Check
Measurement point C642
’
Specified value –29.5 to – 23.5 V
+6 V Check
Measurement point Corrector of Q607
Specified value 5.65 to 6.25 V
Mode E-E
+12 V Check
Measurement point IC601 pin
2
Specified value 11.7 to 12.3 V
+5 V Check
Measurement point Emitter of Q603
Specified value 4.8 to 5.4 V
MTR12 V Check
Measurement point Correcter of Q605
Specified value 12.5 to 14.5 V
F Check
Measurement point ND420
#∞
to
1
Specified value 2.0 to 5.0V
[Check Method]
1)
Each of these supply voltages must meet its specified value.
Power Supply Check
Servo/Video System Adjustments
Audio System Adjustments