Hi Chris,
The old flag-waving trick, eh! TV has bipolar disorder. Thought this prob no longer existed, but it takes me back to the days of tacking resistors on the back of the line modules of K9 TVs.
No mention of it these days, not even on the Philips service website. Note that VCR reproduction on flat screens
was fairly iffey on RF, but most VCRs these days don't have RF Out. I take it you're using Composite Video which was about as sophisticated as older VCRs got. Unsure about the User menu, but there may be something in the
service menu.
If all else fails, you may have to find that pitch fork. You've tried another TV. What about trying another VCR.
"Where on earth am I going to get oneof these?", you ask! Don't know about CH 0, suspect it's no longer relevant these days. Is it possible to change format of TV say, from 1080i to something lower...only a thought.
Bruce