so this is my first time this happened so when it did I wiped the sd card with the files for 3ds homebrew gone and after charging it up when I tried to turn it on it would shine the blue on light for approx. 2 seconds pls help.
this sounds more like a hardware problem, a bricked 3ds should stay on until you turn it off manually
if the 3DS makes a "pop" sound after the 2 seconds of light then the problem is most likely that the ribbon cable for the top screen is loose or disconnected from the motherboard