So I'm playing a Chaos Space Marine (Or a lucky human Renegade), I have power armor, and it's cool. However, you only get to pick between three subsystems, five if you're lucky and rolled "Careful Maintenance" for your armor's history, the others being nonfunctional. The logic behind this is reasonable; wear, tear, and a lack of spares. However, what if I wanted to get all of my armor's subsystems working again? There's nothing in the book that says you can do so, but if it's just a matter of finding the parts, it should be possible. I'd reckon it would require at least an acquisition test to track down the parts to get your magnetic boots or bio-monitor or what have you working again, either by going to see a well-connected Dark Magos who has some spare parts lying around (or can jury-rig a replacement), or by looting the parts off of dead Space Marines/Battle Sisters/any other Imperials wearing power armor. After all, if they're not using it, you may as well.
So what would the rarity be on looking for spare Power Armor subsystem parts? Would there be modifiers if the parts are for Light Power Armor/Legion Power Armor/Terminator armor? Lastly, do you think an armor's Craftsmanship would affect the number of subsystems it would start with?