Doesn't sound like it's this problem, but there were bad capacitors put in tons of electronics for years.
I've rescued several monitors fiing them.
Search for 'bad capacitors' or go to
www.badcaps.com.
Then there are the 2 Sony Trinitrons I have, one's almost 30 years old, the other a few years shy of that.
Net repair cost 50 bucks on one. Biggest issue is the dog ate one of the remotes and only a couple of the Universals will work one of them. One's in my garage, one's a spare in the basement.