Why does my DSi XL turn off when it's closed?

I’ve had my DSi XL since 2011, but since 2018 I think after I dropped it onto a hard floor, the system has developed a habit of turning itself off when the lid is closed. Most of the time it’s when I open it again, but sometimes it’s when nothing’s moving. I’ve heard of issues like this being related to ribbon cables going to the screen, but there doesn’t seem to be any information available to stop the system turning off when the lid is shut. If anyone could help, that would be appreciated.