iPhone 5C doesn't increase battery percentage?

Hi everyone.

I have a problem with my iPhone 5C.

I bought it from a friend of mine, that told me that the smartphone had many issues.

Mainly the problems was the 3.5 jack, that didn't work.

Given that I am able to repair smartphones, I decided to buy a new lightning dock for my iPhone.

After I changed it with the old one, the new jack seemed to work.

Connecting the lightning cable, the smartphone charges the battery.

But 5 minutes later I found out that the battery percentage wasn't increasing.

This fact scared me a lot, because I know that this kind of issue is due to a broken IC near the battery connector (on iPhone 5). So, I remounted the old dock to exclude any damage to the logic board. Fortunately the iPhone started charging the battery normally, but the issue with jack still remains.

I doubted that the component I ordered on eBay was broken, so I tried with another new one. Nothing to do, same story, another day.

Can this be caused by the fact that the components on eBay aren't original?

Thanks in advance,

Roberto.