Your problem is not fuse related. 1 of the fuses is for the charging circuit if it is bad the unit will turn on fine with a properly charged battery. The other fuse is to the power circuit if it is bad no lights will light and you can't charge the battery. Your DSI is flashing on and off because something is shorting. If only 1 screen is flashing the problem is more than likely with the other screen. If both screens are flashing then it could be because of water damage, improperly seated cables - more than likely 1 of the ribbon cable to the screens or a bad upper screen ribbon cable that goes through the hinge. This guide here will help you tear it down to inspect for water damage and how to get to the cables. If you find residue or other signs of liquid damage please see the water damage tag for solutions to that. Your ribbon cables need to be sitting square and true to the socket they go in. Please be sure the flap that holds the ribbon cable in is flat and even, sometimes they like to bow up or out in the center. If you are certain there is no water damage and that all the cables are seated properly more than likely the upper LCD will need replaced because there is damage to the attached ribbon cable - even if signs of damage aren't visible. That part is available here. The same guide will apply.