Panasonic Omnivision VHS PV-C2780, Service Manual

Page: 52 / 185

1. Place a jumper between TP6003 and+5V(TP6009) on the TV/VCR
Main C.B.A. to defeat Auto Tracking.
2. Eject the tape and insert it again to access the Neutral Tracking
position.
3. Play back the alignment tape.
4. Connect the oscilloscope to TP3002 on the Video Signal Process
Section of the TV/VCR Main C.B.A. Use TP6205 as a trigger.
5. Confirm that the RF envelope is flat enough (V1/V-max. is 0.7 or
more). If not, with Post Adjustment Driver, adjust P2 and P3 post
height so that the envelope waveform becomes as flat (V1/V-
max.is 0.7 or more) as possible (No envelope drop). If the
envelope drop appears on the left-half of the waveform, adjust P2
post height. If the envelope drop appears on the right-half of the
waveform, adjust P3 post height.
CAUTION:
Overtightening P2 and P3 posts may cause the threads to strip.
Note:
It will be possible to confirm Step 5 according to following steps.
A. Press the Tracking Control Up or Down button on remote
control. Make sure that the envelope waveform remains flat. If
not, readjust P2 and/or P3 post heights.
Fig. M4-1
Fig. M4-2
6. After adjustment, confirm that the tape travels without curling at
52