My DS has the power light on but it isn’t turning on.

I don’t know what happened, but my DS lite one day wouldn’t turn on. When I press down on a certain spot near the X button, it powers on but crashes after a couple seconds. I tried looking at the battery, nothings wrong with it. The green “on” light is on but the screens are black and there’s no sound. Please help! This DS is very special to me.