- 16 -
MECHANICAL ADJUSTMENTS
2-2: CONFIRMATION AND ADJUSTMENT OF AUDIO/
CONTROL HEAD
When the Tape Running Mechanism does not work well,
adjust the following items.
1.
2.
3.
4.
Playback the VHS Alignment Tape
(JG001C or JG001E)
.
(Refer to SERVICING FIXTURE AND TOOLS)
Confirm that the reflected picture of stamp mark is
appeared on the tape prior to P4 Post as shown in
Fig.
2-2-A
.
a)
b)
Turn the screw to set the audio level to maximum.
Confirm that the bottom of the Audio/ Control Head and
the bottom of the tape is shown in
Fig. 2-2-C
.
c)
When the reflected picture is distorted, turn the screw
1 clockwise until the distortion is disappeared.
When the reflected picture is not distorted, turn the
screw counterclockwise until little distortion is
appeared, then adjust the a).
When the height is not correct, turn the screw
to
adjust the height. Then, adjust the 1~3 again.
Fig. 2-2-A
Audio/Control Head
Reflected picture of
Stamp Mark
P4 Cap
Stamp Mark
Fig. 2-2-B
Audio/Control Head
Fig. 2-2-C
Audio/Control Head
Tape
0.25± 0.05mm
2-3: TAPE RUNNING ADJUSTMENT
(X VALUE ADJUSTMENT)
1.
2.
3.
4.
5.
6.
7.
Confirm and adjust the height of the Reel Disk.
(Refer to item 1-1)
Confirm and adjust the position of the Tension Post.
(Refer to item 1-2)
Adjust the Guide Roller.
(Refer to item 2-1)
Confirm and adjust the Audio/Control Head.
(Refer to item 2-2)
Connect CH-1 of the oscilloscope to
TP102
, CH-2 to
TP103
and CH-3 to
pin 19 of J8004
.
Playback the VHS Alignment Tape
(JG001U or JG001V)
.
(Refer to SERVICING FIXTURE AND TOOLS)
Set the X Value adjustment driver
(JG153)
to the of
Fig. 2-2-B
. Adjust X value so that the envelope waveform
output becomes maximum. Check if the relation between
Audio and Envelope waveform becomes (1) or (2) of
Fig.
2-3
.
Fig. 2-3
Envelope
(1)
CH-3
Audio
(2)
2-4: CONFIRM HI-FI AUDIO (Hi-Fi model only)
1.
2.
3.
4.
5.
Connect CH-1 of the oscilloscope to
TP103
and CH-2 to
the
pin 19 of J8004
.
Playback the VHS Alignment Tape
(JG001R)
.
(Refer to SERVICING FIXTURE AND TOOLS)
Press the Tracking Up button and count number of steps
which the audio output is changed from Hi-Fi (10KHz) to
MONO (6KHz).
Press the Tracking Down button and count number of
steps which the audio output is changed from Hi-Fi
(10KHz) to MONO (6KHz).
If the difference are more than 3 steps, set the X Value
adjustment driver
(JG153)
to of
Fig. 2-2-B
. Change the
X Value and adjust it so that the value becomes within 2
steps.
1
2
3
1
4
3
2
4
4
