Philips MX5100VR/00, Руководство по обслуживанию

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1-9-1 E9515EA
ELECTRICAL ADJUSTMENT INSTRUCTIONS
General Note: "CBA" is an abbreviation for
"Circuit Board Assembly."
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 proce-
dures, make sure that the tracking control is set in
the center position: First, press the "VCR" button
on the remote control unit to put the System in
VCR mode. Second, press either "
L
CH
??
" or "
K
CH"
button on the remote control unit, then press the
"PLAY" 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 point 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 (416.0
µ
s
±
60
µ
s) delayed posi-
tion from the rising edge of the CH2 head switching
pulse waveform.
Test point Adj.Point Mode Input
TP751(V-OUT)
TP504(RF-SW)
GND
VR501
(Switching Point)
(MAIN CBA)
PLAY
(SP)
-----
Tape
Measurement
Equipment
Spec.
FL6A Oscilloscope
6.5H
±
1H
(416.0
µ
s
±
60
µ
s)
Connections of Measurement Equipment
Oscilloscope
Main CBA
TP751
CH1 CH2
Trig. (+)
GND
TP504
Figure 1
EXT. Syncronize Trigger Point
1.0H
CH1
CH2
Switching Pulse
V-Sync
0.5H
6.5H
±
1H (416.0
µ
s
±
60
µ
s)