I know this problem, and it does happen to other laptops too (not only Acer laptops, also HP, Compaq, Asus, all of them).
It is a bad connector, the connector isn't well solded to the motherboard.
It is an production error!
And it happens to more people.
HP, Compaq, Asus, Dell, Packard Bell, all laptops can have a problem like this but it is very rare.
It doesn't happen a lot, but it does sometimes.
People say Acer is bad, because of this problem.
But this isn't the truth!
I had an old Aspire 1400 and it worked for over 8 years!
The same for my Aspire 5520, that works for over 4 years now.
Newer models are fine too.
There is nothing wrong with Acer laptops, you only have one that is badly made.
It doesn't matter what type of laptop you have, there are always a few laptops with production errors.
And it happen to all brands, even Asus, HP, Compaq, every brand.
You just had the one with the bad connector.
If you go back to the dealer you should get a free repair (if you still have warranty).