i have ipad mini dont start ?

Dear apple support team

I have Ipad mini don't start,I buy it before one month ,last time I use it the battery was finish and I but it in charger ,when I come back to the Ipad was not charging and not display any thing in the screen.

I try to check every thing was good (charger ,cable,power) I try another Ipad in the same charger it was charging with out any problem .

when it was in the charger nothing in the screen was display

I go to work shop to fix it but they told me this problem it was in many of Ipad mini and they can not fix it.

please help me to try fix it and resolve this issue