It's a Zenith VCS442. Worked fine until the video playback started to look
like the heads needed cleaning (fuzzy picture a bit like bad tracking, but
audio OK), tried a wet cleaning casette, no help; opened it up and cleaned
the rotating drum and 2 stationary heads (erase and audio?) with a foam
swab and alcohol, then dry swabbed and waited 5 mins to dry further.
Seemed to solve the problem, but the next day the problem reappeared; did
same cleaning routine and again it seemed to do the job, but this time less
than a half hour later the video was totally blank (though it looks almost
normal on CUE and REW).

Seems like if I 'fix' it again it just might bite somebody.

Is this just another way VCRs go defunct or is there something else that
can be done? I'm strictly an amateur with, apparently, just enough repair
skills to cause damage. I bought it 2nd hand at a thrift store a few months
back.