"Fuzziness" is too...fuzzy a term to say for sure. A lack of focus can be caused by anything from poor adjustment of the focus circuitry, to a misbehaving high-voltage supply, to a worn out CRT. Without more data, you can't say which of these (if any) is the problem.

If it does turn out to be the CRT (rare, in my experience), then you can use a CRT from any of the compacts.