Some of the time a 'repair' ticket is fulfilled by a simple cleaning. When a simple cleaning won't do a hardware replacement may be the solution. Every stage of your repair is documented and can be tracked by you, the customer, over email.
A slow device no matter what the type (Mac, Windows, Android, Unix, iOS etc) is easily fixable. A quick cleaning, internal and external, is the most common solution. Sometimes it needs a deep clean. Sometimes a new battery. Before all cleaning operations the device is backed up (if you choose) on my secure server that is wiped after every successful Tune-Up.
I can usually get all of those precious videos of your cat, photos of your kids, and those project files back; I can recover most if not all of your data and back it up on our secure in-house server, Google Drive, or provided external HDD/SSD/Flash Drive.