LG Motherboards & SD Cards

A

AC Question

I am randomly receiving this "boot certificate error", on an old LG phone; a phone in which I need to get turned on so that way, I may extract the encrypted contents off my SD card. My question is however, if I would to buy a brand new motherboard for that particular phone, will I still be able to see the contents of my card? Like before whenever I needed to do a "factory reset," my contents were still there. "Or", will I need to get that phone flashed or working with that motherboard in order for it to work?