FUNAI WD6D-M100, Service Manual

Page: 18 / 99

1-7-1 E9TF0EA
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
completed. Also, do not attempt these adjustments
unless the proper equipment is available.
2. To perform these alignment / confirmation
procedures, make sure that the tracking control is
set in the center position: Press either [PROG.
?K
]
or [PROG.
?L
] button on the front panel first, then
the [
B
] (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
waveform 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
J171(V-OUT)
TP504(RF-SW)
GND
VR501
(Switching Point)
(AV CBA)
PLAY
B
(SP)
-----
Tape
Measurement
Equipment
Spec.
FL6A Oscilloscope
6.5H
±
1H
(416
µ
s
±
64
µ
s)
Connections of Measurement Equipment
Figure 1
Oscilloscope
AV CBA
J171
CH1 CH2
Trig. (+)
GND
TP504
EXT. Syncronize Trigger Point
1.0H
CH1
CH2
Switching Pulse
V-Sync
0.5H
6.5H
±
1H (416
µ
s
±
64
µ
s)