1 - XL MUST see your SD-card
2 - navcore + maps MUST be on SD-card
3 - damaged internal memory MUST NOT shorten device.
PS If your XL has SD-slot, and device won't start from it - try to un-solder internal memory from plate. In this case not necessary to change it with micro-sd card at all. If no SD-slot - then you must replace internal with SD/microSD.