Recapping
If it has the sealed aluminum caps, you shouldn't have to recap it. If it has paper caps or black bumblebee caps, you have to recap it. The old paper caps and bumblebees leak DC voltages across the terminals of the capacitor. This can damage a lot of things within the circuit with prolonged use. Any paper capacitors, even if tested to not leak, are still supposed to only last 15 years. If there in there, get them out.