Acura TL repair

Nayramoney53 seconds ago
I purchased a 07 Acura TL about 2 weeks later the
starter died on me, I tapped it and got it started
took it to my mechanic and ordered a new starter I
had all the fuses and cables checked, about 3 days
with the new starter and I again couldn't start it,
again tapping on the starter started it up.I was told
by the mechanic that it must be a defective part but
I'm nervous that it could be something else, like I
said there's no corrosion in cables or anything else
that I can think of. Any thoughts as to what else it
could possibly be?