Hitachi DV-PF6E, Service Manual

Page: 70 / 123

5-6
1-A. Preliminary/Final Checking and
Alignment of Tape Path
Purpose:
To make sure that the tape path is well stabilized.
Symptom of Misalignment:
If the tape path is unstable, the tape will be damaged.
Note: Do not use an Alignment Tape for this proce-
dure. If the unit is not correctly aligned, the tape may
be damaged.
1. Playback a blank cassette tape and check to see
that the tape runs without creasing at Guide Roll-
ers [2] and [3], and at points A and B on the lead
surface. (Refer to Fig. 5-4-3 and 5-4-4.)
2. If creasing is apparent, align the height of the
guide rollers by turning the top of Guide Rollers [2]
and [3] with a Guide Roller Adj. Screwdriver. (Refer
to Fig. 5-4-3 and 5-4-5.)
3. Check to see that the tape runs without creasing at
Take-up Guide Post [4] or without snaking between
Guide Roller [3] and ACE Head. (Fig. 5-4-3 and 5-
4-5)
4. If creasing or snaking is apparent, adjust the Tilt
Adj. Screw of the ACE Head. (Fig. 5-4-6)
1-B. X Value Alignment
Purpose:
To obtain maximum PB FM envelope signal at the pre-
set position of the Tracking Control Circuit, align the
Horizontal Position of the ACE Head.
Symptom of Misalignment:
If the Horizontal Position of the ACE Head is not prop-
erly aligned, maximum PB FM envelope cannot be
obtained at the preset position of the Tracking Control
Circuit.
1. Connect the oscilloscope to TP301 (C-PB) and
TP503 (CTL) on the Main CBA. Use TP504 (RF-
SW) as a trigger.
2. Playback the Gray Scale of the Alignment Tape
(MH-2) and confirm that the PB FM signal is
present.
3. Set the Tracking Control Circuit to the preset posi-
tion by pressing CH UP button on the remote con-
trol unit then “PLAY” button on the unit. (Refer to
note on bottom of page 5-7.)
4. Use the Flat Screwdriver so that the PB FM signal
at TP301 (C-PB) is maximum. (Fig. 5-4-6)
Guide Roller [2]
Guide Roller [3]
A
B
Take-up Guide Post [4]
ACE Head
Fig. 5-4-3
Lead Surface of Cylinder
Tape
Fig. 5-4-4
Take-up Guide
Post
Tape
Guide Roller
Tape
Correct
Incorrect
Fig. 5-4-5
Azimuth Adj. Screw
Flat
Screwdriver
Tilt Adj. Screw
ACE Head
Fig. 5-4-6