Repair and modification are not the same thing

A repair aims to restore intended operation; a modification intentionally changes characteristics, configuration or response. In practice the boundary can overlap.

For example, replacing a failed component with an equivalent may be service work; selecting a different value or technology to alter the sound is also a modification.

Document the initial problem, work performed, removed components and result.

This distinction is more useful than broad labels such as “serviced” or “professionally upgraded”.