OK watched the video, that was exiting ! And informative....
A good working TV will give what we called good snow & a
nice loud waterfall sound without signal. Yours does not.
Snow should be dots without streaks & lots of contrast.
Changing channels on yours does not show any switch noise
that I can see. Everything points to IF problem.
Try freeze mist. After warm up spray some on a Q-tip then
hold it to the IF transistors one at a time. If no joy with 1st IF
let it warm up again then try 2nd etc. It may be just as easy
to change all 3 ONE AT A TIME ! I used ECG replacement with good luck
except when I worked at Sony Service, then it was OEM
needless to say.
One other thing about all early Jap sets is they were ALL very
unstable after a few years. They used crap electrolytics.
Aim to get the IF's "hot" again & deal with any instability
later.
73 Zeno
