I never had a problem with my 5 year old Mac but this morning it shut down completely so I took it to the Apple Store and they plugged it into some diagnostic machine and discovered a dead battery and a faulty power cord.
So the Apple person took each item off the shelf, unwrapped them, installed them. and ran it through another diagnostic program to insure that it ran as good as new.
The parts alone came to more than $120 but there was no charge at all.
I know of no other computer company that provides the service that Apple does.
Apple always seem to treat their customers as friends and is always ready to answer any questions about the hardware and the software even if it take a lot of time to explain it thoroughly.