Sony SLV-7700KME, Service Manual

Page: 96 / 135

7-2
2-1-4. Alignment Tape
• Contents of MH-2 (Normal-VHS)
Mode Period Video signal Audio signal
1 10 minutes Stair step 7kHz
2
SP
5 minutes 3kHz
3 10 minutes Color bar 1kHz
4 3 minutes RF sweep
2-1-5. Specified Input-output Level and the Impedance
LINE-1/2 IN
VIDEO IN, phono jack (1 each)
Input signal: 1 Vp-p, 75
Ω
,
unbalanced, sync negative
AUDIO IN, phono jack (2 each)
Input level: 327 mVrms
Input impedance: more than 47 k
Ω
LINE-1/2 OUT
VIDEO OUT, phono jack (1)
Output signal: 1 Vp-p, 75
Ω
,
unbalanced, sync negative
AUDIO OUT, phono jack (2)
Standard output: 327 mVrms
Load impedance: 47 k
Ω
Output impedance: less than 10 k
Ω
Video CD DIRECT OUT
VIDEO OUT, phono jack (1)
Output signal: 1 Vp-p, 75
Ω
,
unbalanced, sync negative
AUDIO OUT, phono jack (2)
Standard output: 2.0 Vrms max
Load impedance: 47 k
Ω
Output impedance: less than 600
Ω
2-1-6. Adjustment Procedures
Perform the adjustment following the procedures given below.
2-2. VIDEO-CD COLOR-BARS MODE
On this mode, the data of the color-bars signal as a picture signal
and the 1 kHz sine wave signal as a sound signal are output by the
mechanism control microcomputer (IC301) for video CD signal
check. When measurement of the voltage and waveform on the CD-
169 board, perform it in this mode.
For reference, the color-bars signal can be observed at Video CD
DIRECT OUT (VIDEO) terminal and the sound signal can be
observed at Video CD DIRECT OUT (AUDIO) terminal using an
oscilloscope.
[Setting Method]
1)
Turn the power on.
2) Connect the SOL303 on the CD-169 board with solder.
3) After measuring, remove the soldering installed.
Fig. 7-2-3. Color bar signal of the Color-bars mode
Power supply check
Servo system
adjustment
Video System
adjustments
Audio System
adjustments
Video CD system
adjustment
White (100%)
Red
Approx.
0.7V
Approx.
0.3V
Approx.
0.3V
Burst signel (Should be flat)
Horizontal synchronizing signal