JVC DR-MV2SEU Service Manual page 33

4.4.2.1 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 procedure. 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 Rollers [2] and [3], and
at points A and B on the lead surface. (Refer to Fig. 3 and
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. 3 and 5.)
Guide Roller [2]
A
Take-up Guide Post [4]
Lead Surface of Cylinder
Correct
Guide Roller
Tape
Take-up Guide
Post
Tape
(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. 3 and 5)
Guide Roller [3]
ACE Head
B
Fig.3
Tape
Fig.4
Incorrect
Fig.5
(4) If creasing or snaking is apparent, adjust the Tilt Adj. Screw
of the ACE Head. (Fig. 6)
Azimuth Adj. Screw
ACE Head
Tilt Adj. Screw
4.4.2.2 X Value Alignment
Purpose:
To obtain maximum PB FM envelope signal at the preset po-
sition of the Tracking Control Circuit, align the Horizontal Posi-
tion of the ACE Head.
Symptom of Misalignment:
If the Horizontal Position of the ACE Head is not properly
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 trig-
ger.
(2) Playback the Gray Scale of the Alignment Tape
(FL6NS8) and confirm that the PB FM signal is present.
(3) Set the Tracking Control Circuit to the preset position by
pressing "PR +" button and then " " button on the unit.
(Refer to note on bottom of page 1-34.)
(4) Use the Flat Screwdriver so that the PB FM signal at
TP301 (C-PB) is maximum.(Fig. 6)
(5) To shift the CTL waveform, press "PR +"or "PR -"button
on the remote control unit. Then make sure that the max-
imum output position of PB FM envelope signal becomes
within ±2ms from preset position.
Flat
Screwdriver
Fig.6
(No.YD087)1-33