I have a 51" Sony KP-51WS510. It is a RP-CRT Set.
I've owned it for about 4 1/2 to 5 years now, and during the first ~4 years of its life I'd say it had been on for 12-16 hours of the day. After my baby was born 9 months ago the TV ended up staying on 20+ hours a day. I refuse to watch a 4:3 picture stretched so the screen now suffers from burn-in from the bars on either side of the picture.
That is not the problem.
Aside from the burn-in, I have no real problems with the set. Powers on every time, picture does not fade or blink or distort, etc. It's obviously not as bright anymore (especially in that 4:3 viewing area) but that's to be expected.
However in the last 2 weeks I've noticed something. Upon powering the set on AND off, there is a few seconds of crackling and popping. Not coming from the speakers, but from the set itself. It used to make no sound like this what-so-ever, other than the single "click" it always made. It is an electric-sounding crackle, more distinct than that usually associated with the static from powering a CRT on or off. I've had the TV on mute for the past hour or so watching things on my computer, and have heard intermittent single crackles and pops. I have not moved the TV recently, it's been in the same spot, with the same AV equipment for 2 years.
Again, there is no change in the picture while I'm watching it as these crackles occur, and thus far the TV has never failed to power on. Other than the burn-in and dimmer picture the set functions perfectly fine. I'm no wiz, but I've fixed a couple CRTs before, mostly in old arcade cabs and mostly relating to the chassis-board. I've googled a couple different relevant search terms and came up with nothing too specific other than flyback transformers and voltage being too high.
Should I expect a failure of the set soon? I know it's been used and over-used in its lifetime so I would not be surprised. Are there preventative steps I can take? If it's beyond my capabilities or budget what sort of prognosis am I looking at? I've been thinking about upgrading to an LCD or Plasma set, but don't have the money at the moment and honestly (since I'm not in the market) haven't done the research so this would be a bad time to lose my set.