@iphone1345958 if it just vibrates but does not show anything on the screen, that is usually caused by a bad display. I would consider changing it and since you have to open it for that, replace the battery as well. Then re-evaluate.
Download the [link|https://support.lenovo.com/au/en/docs/UM101283|Service Manual|new_window=true] for your Lenovo Tab 2 A7-30 for the repair.
While you work on your tablet, take lots of pictures. Once you are done with it, take those pictures and create a guide for iFixit. That will help the next person that has the same problem as you do. It's easy and fun to create these guides. https://ifixit.com/Guide/new The iFixit community will appreciate this.