Mac Pro 5,1 Missing internal serial number. I really want to be able to boot into recovery. For the longest time I couldn't remember the password. Then I used the calculator bit flipping technique and what do you know!! I remember that password! However! When I try to boot into recovery (holding command-R), the padlock comes up, but neither the mouse nor the keyboard are active/functining.. Regardless of which port I use. I really want to upgrade this machine to a fast 12-core rig but I'm quite worried there is a firmware virus or something on the motherboard. Please help! I have a SOIC adapter and raspberry PI and would love to get cracking on reflashing but I would need decent instructions, most of the online stuff refers to macbook issues..... p.s. nice to be posting here after a decade of lurking!