Originally Posted by Captainclock
I have an oscilloscope but have no idea how to use it.
Also what if the audio works fine on another tape that's the same vintage?
I'm wondering because I tried another all analog VHS Tape from 1988 that when I played it it had no problems playing Hi-Fi Audio without cutting back and forth between Hi-Fi and Linear Stereo audio like the Monty Python tape did.
Someone needs to show you how to check tape path alignment with an o'scope. Very important test and observation when servicing VCRs.
One way to test if the hi-fi heads are worn or partially clogged, would be to record and playback. If one or both heads are not working properly recording and playback will bring out the problem. If it does that with solid hi-fi tracking and no audio noise the heads are probably fine. Seen many VCRs in the day that would play back hi-fi on good tapes but would have flutter noise or just not switch to hi-fi at all on self-recordings if the hi-fi heads were too worn.
The Monty Python tape could have been recorded a bit out of alignment or head switching point was off, or the tape is damaged, stretched or curled along an edge, don't know and can't tell without looking.