When does an instrument need a check-up?

If the instrument has started buzzing persistently, tiring you out or losing its tuning, it's worth a technical check. The same goes for signal dropouts, loose parts and a noticeable change in string height.

A change of gauge or tuning may also call for the setup to be adjusted. If there are cracks, a lifting bridge or serious warping, don't try to compensate with random adjustments.

Before you bring the instrument in, note when the symptom appears and what changed beforehand. The string set, the tuning and the way you play all help with the diagnosis. The goal of a service is to deal with the real cause and do the work that particular instrument needs.