The most common call from this part of the service area is an opener that runs but the door doesn't move, or a motor that hums and then stops. On a 20-plus-year-old unit, that's usually the drive gear stripped inside the housing - a plastic gear that's not built to outlast the motor around it, and by 2001 that gear has had a couple decades of Arizona garage heat to get brittle. When that happens, repair almost never makes sense; the gear kit costs close to what a new opener runs, and the rest of the unit is the same age.
A second common symptom: the opener works from the wall button but not the remote, or vice versa. That's more often a dying circuit board than a wiring fault, and on a unit this old it's usually the tipping point where replacement is the straightforward call rather than a board swap.
If your door won't open at all - cables, springs, or the track itself - that's a different job than opener installation. Our repair page covers that side of things directly.