Panasonic PV-D4742 Service Manual page 47

To confirm that the tape runs smoothly. In particular, confirm that
the tape properly picks up the Audio Signal at the upper part of
the head and the Control Signal at the lower part of the head.
Symptom of Misadjustment:
If the tilt of the Audio Control Head is poorly adjusted, the tape
will eventually be damaged. An intermittent Blue screen may be
seen in Playback.
1. Play back a T120 cassette tape and check that the tape travels
smoothly between the upper and lower guides of the P4 post.
2. If necessary, adjust Black Screw (B) clockwise until the tape
begins to curl at the lower edge of the P4 post. Then adjust the
screw counterclockwise until the curling is eliminated.
6.2.2.2.3. AUDIO CONTROL HEAD HEIGHT ADJUSTMENT
The height of the Audio Control Head replacement part is preset at the factory.
Purpose:
To be sure the tape runs properly along the Control Head.
Symptom of Misadjustment:
If the control signal is not properly picked up, Servo Operation
cannot be achieved. A Blue screen will be seen in Playback.
This confirmation is required when the Audio Control Head is replaced.
1. Play back a T120 cassette tape and check that the lower edge of
the tape runs approximately 0.25 mm above the lower edge of the
Audio Control Head.
2. If necessary, adjust Black Screws (A) and (B) clockwise to lower
the tape or counterclockwise to raise.
Fig. M4
Fig. M5
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