ELECTRICAL ADJUSTMENT INSTRUCTIONS
General Note: "CBA" is an abbreviation for
Head Switching Position Adjustment
"Circuit Board Assembly."
Purpose:
NOTE:
To determine the Head Switching position during
1.Electrical adjustments are required after replacing
playback.
circuit components and certain mechanical parts.
It is important to do these adjustments only afterSymptom of Misadjustment:
all repairs and replacements have been com-May cause Head Switching noise or vertical jitter
pleted. Also, do not attempt these adjustmentsin the picture.
unless the proper equipment is available.
2.To perform these alignment / confirmation proce-Test pointAdj.PointModeInput
dures, make sure that the tracking control is set in
the center position: Press either "L5??" or "K" buttonJ23(V-OUT)VR501
PLAY
on the remote control unit first, then the "PLAY"TP502(RF-SW)(Switching Point)-----
(SP)
GND(MAIN CBA)
button (Front Panel only).
Measurement
Test Equipment RequiredTapeSpec.
Equipment
1.Oscilloscope: Dual-trace with 10:1 probe,
6.5H?1H
V-Range: 0.001~50V/Div., FL6AOscilloscope
(416.0?s?60?s)
F-Range: DC~AC-20MHz
2.Alignment Tape (FL6A)Connections of Measurement Equipment
Oscilloscope
J23
Main CBAGND
TP502
CH1 CH2
Trig. (+)
Figure 1
EXT. Syncronize Trigger Point
CH1
1.0H0.5H
6.5H
CH2V-Sync
Switching Pulse
Reference Notes:
Playback the Alignment tape and adjust VR501 so that
the V-sync front edge of the CH1 video output wave-
form is at the 6.5H(416.0?s) delayed position from the
rising edge of the CH2 head switching pulse wave-
form.
1-6-1HG240EA |