Question

Why the smart phone is not charging when I plug in?

Answer 1

Is it off or on, when you try to charge it?

If it`s on and it doesn`t charge at all, at least this is what you see, send it to a service

If it`s off, it possible not to see a charging icon on the background, depending on your smartphone. For example on HTC models, you will have to turn it on to see whether it`s charged or not, you don`t see any progress in background

Answer 2

Have you checked if your charger is working on another smartphone same as yours (or same connectors as yours)? I had a charger who I didn't know was broken or faulty until I noticed that sometimes it charges the phone and when you moved the phone, charging stops. It has a loose connection to the phone or probably the wire of the conector was cut.

Answer 3

try to remove your battery and put it again then switch it on and charge it or try to
check if the charger works

Answer 4

There are cases that some smartphones wont charge on universal charger.  Before you send it to the service center, try charging it first using the original branded charger.