Philips MX5100VR/00 Service Manual page 136

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 Rollers
[2] and [3], and at points A and B on the lead sur-
face. (Refer to Fig. M3 and M4.)
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. M3 and M5.)
Guide Roller [2]
A
Take-up Guide Post [4]
Lead Surface of Cylinder
Correct
Guide Roller
Tape
Take-up Guide
Post
Tape
Guide Roller [3]
ACE Head
B
Fig. M3
Tape
Fig. M4
Incorrect
Fig. M5
3. Check to see that the tape runs without creasing at
Take-up Guide Post [4] or without snaking between
Guide Roller [3] and AC Head. (Fig. M3 and M5)
4. If creasing or snaking is apparent, adjust the Tilt
Adj. Screw of the AC Head. (Fig. M6)
Azimuth Adj. Screw
AC Head
Tilt Adj. Screw
1-B. X Value Alignment
Purpose:
To align the Horizontal Position of the Audio/Control/
Erase Head.
Symptom of Misalignment:
If the Horizontal Position of the Audio/Control/Erase
Head is not properly aligned, maximum envelope can-
not be obtained at the Neutral 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
(FL6NS8) and confirm that the PB FM signal is
present.
3. Set the Tracking Control Circuit to the center posi-
tion by pressing "VCR" button and "KCH" button
on the remote control unit then pressing "PLAY"
button on the unit. (Refer to note on bottom of page
2-3-4.)
4. Use the X-Value Adj. Screwdriver so that the PB
FM signal at TP301 (C-PB) is maximum. (Fig. M6)
5. Press "KCH" button on the remote control unit until
the CTL waveform has shifted by approx. +2msec.
Make sure that the envelope is simply attenuated
(shrinks in height) during this process so that you
will know the envelope has been at its peak.
2-3-3
X-Value Adj.
Screwdriver
Fig. M6
E9015MA