Hi @dimmmmy,
Is the screen cracked?
If so there may be more internal damage in the tablet that is preventing the tablet from starting.
It may be better to open it up first and check.
Here's the [https://download.lenovo.com/consumer/mobiles_pub/lenovo_tab_2_a7_hmm_en_v1.0_201509.pdf|hardware maintenance manual] for the tablet, that will help.
If there are any obviously damaged parts, then the manual has a parts list which help you to find the replacement parts. Search online using the FRU number to find suppliers.
Here's the ifixit [guide|99254] video as well.