Why won't it charge

I've just got an IPAD 4 delivered to me where the owner has changed battery and since i had an extra battery he wanted me to test it with another battery. After he changed battery it will not charge. I've testet with another battery and same result, the "charing" symbol shows up in uppler right coner and as soon as plugged into power it turns on if it's of.

Any tip of what it can be and how to solve it ?