Panasonic PV-M1348, Service Manual

Page: 44 / 130

2-21
Hole (A)
FG Head
Capstan Belt
Capstan Rotor
Unit
0.13 +/- 0.02mm
Screwdriver
Black
Screw (A)
FG HEAD GAP ADJUSTMENT
Purpose:
To properly pick up the FG Signal.
Symptom of Misadjustment:
If the FG Signal is not properly picked up, Servo Operation
cannot be achieved.
Equipment Required:
Oscilloscope
Specification .............................................. 0.13 +/- 0.02mm
1. Remove the VCR Chassis Unit and then place it upside
down.
2. Remove the Main C.B.A.
3. Slightly loosen Black Screw (A). Then set the Screwdriver
(#1 or #2 Phillips Driver) into the Hole (A). Turn the
screwdriver counterclockwise until the FG Head touches
the rotor. Then turn it slightly clockwise to the clearance as
specified.
4. Tighten Black Screw (A).
5. Reinstall the Main C.B.A.
Fig. M4
Note:
Do not touch the outside circumference of the rotor surface
with any tool and keep magnetic material away
from the rotor magnet (especially metal particles).
Confirmation of Signal Level
1) Supply a Video Signal to the Video Input Jack.
2) Insert a cassette tape and place the unit in SLP recording
mode.
3) Connect the oscilloscope to Pin 7 of P2502 on the Capstan
Stator Unit.
Confirm that the signal level is greater than 15mVp-p.
P2 AND P3 POST HEIGHT ADJUSTMENT
(PRELIMINARY ADJUSTMENT)
Purpose:
To properly align the position of the tape with the Cylinder
Lead so that the tape runs with stability.
Symptom of Misadjustment:
1) Since the Envelope Waveform Signal cannot be tracked
properly, the Playback picture will be poor.
2) Since the tape does not run smoothly, the tape will
eventually be damaged.
3) Tape interchangeability is poor.
Equipment Required:
Post Adjustment Plate .............................. (VFKS0010)
Reel Table Height Fixture ......................... (VFKS0009)
Post Adjustment Driver ................................ (VFK0329)
1. Remove the Cassette Up Ass'y.
2. Position the Post Adjustment Plate over the reels.
3. Place the fixture on the Post Adjustment Plate and zero the
fixture (DO NOT use the cut-out portion of the post
adjustment plate.)
Fig. M5-1
4. Lower each post below the top edge of the Post Adjustment
Plate. Then, raise each post until it contacts the foot of the
Reel Table Height Fixture. For proper adjustment, the foot
of that should be positioned as shown.
Fig. M5-2
Fig. M5-3
CAUTION:
1) Overtightening P2 and P3 posts may cause the threads
to strip.
2) Upon completion of this procedure, perform the "Envelope
Output Adjustment" procedures.
VFKS0010
P2
P3
(Post Adjustment Plate)
VFKS0010
VFKS0009
(Fixture)
First Lower
Then Raise Post
Upper Edge of
Lower Tape Guide
Foot
Post Side View Back View
Foot
NO GOOD GOOD
(a)
(b)