Three thoughts
1 Check to see if there is a capacitor on the Cylinder motor and
replace it.. I had other brands with this problem.

2 I recall having vertical problems on some emerson tv/vcr which both
units must have shared the same 9 volt supply. The 9v supply feed
either pin 1 or 2 of the vertical Ic ( not the main supply to the chip)
and when pushing play on the vcr the set would go into vertical colasp.
May 9v just slightly week in your case.

3. . Do a google search on ESR circuits and you should find a set up
using you signal generatoe and scope...Sorry Indon't have it
bookmarked.