1-7-1
E9G02EA
ELECTRICAL ADJUSTMENT INSTRUCTIONS
NOTE:
1.Electrical adjustments are required after replacing
circuit components and certain mechanical parts.
It is important to do these adjustments only after
all repairs and replacements have been com-
pleted. Also, do not attempt these adjustments
unless the proper equipment is available.
2.To perform these alignment / confirmation proce-
dures, make sure that the tracking control is set in
the center position: Press either [PROG.
L
] or
[PROG
.
K
] button on the front panel first, then the
[PLAY] (VCR) button on the front panel.
Test Equipment Required
1.Oscilloscope: Dual-trace with 10:1 probe,
V-Range: 0.001~50V/Div.,
F-Range: DC~AC-20MHz
2.Alignment Tape (FL6A)
Head Switching Position Adjustment
Purpose:
To determine the Head Switching position during
playback.
Symptom of Misadjustment:
May cause Head Switching noise or vertical jitter
in the picture.
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
±
1H (416
µ
s
±
64
µ
s) delayed position
from the rising edge of the CH2 head switching pulse
waveform.
Test point
Adj.Point
Mode
Input
J236(JK1-V-OUT)
TP504(RF-SW)
GND
VR501
(Switching Point)
(MAIN CBA)
PLAY
(SP)
-----
Tape
Measurement
Equipment
Spec.
FL6A
Oscilloscope
6.5H
±
1H
(416
µ
s
±
64
µ
s)
Connections of Measurement Equipment
Oscilloscope
BOARD
Main
J236
CH1 CH2
Trig. (+)
GND
TP504
Figure 1
EXT. Syncronize Trigger Point
CH1
CH2
1.0H
0.5H
V-Sync
Switching Pulse
6.5H
±
1H (416
µ
s
±
64
µ
s)
Summary of Contents for W4A-A4180DB
Page 17: ...1 6 5 E9G02DC Fig D10 20 Deck Pedestal 21 Front Bracket R S 19 S 19 S 19 S 19 S 20...
Page 39: ...1 12 6 E9G00SCM4 Main 4 9 Schematic Diagram VCR Section...
Page 40: ...1 12 7 E9G00SCM5 Main 5 9 Schematic Diagram VCR Section...
Page 41: ...1 12 8 E9G00SCM6 Main 6 9 Front Jack Schematic Diagram VCR Section...
Page 42: ...1 12 9 E9G00SCM7 Main 7 9 Schematic Diagram VCR Section...
Page 43: ...1 12 10 E9G00SCM8 Main 8 9 Schematic Diagram VCR Section...
Page 44: ...1 12 11 E9G00SCM9 Main 9 9 Schematic Diagram VCR Section...
Page 46: ...1 12 13 E9G00SCRJ Rear Jack Schematic Diagram VCR Section...
Page 85: ...W4A A4180DB W4A D4180DB W4D D4180DB E9G00 03 04ED 2007 06 18...