The non-functional apparati... apparatusses...appartuses? If i recall were just the ones that were baddly damaged during the rise of Sky and the explosion that crippled Delkfutt and Fei'Yin... Which would explain Fei'Yins unlit status, as well as Ranguemount(?) Pass. KRT's nonfunctional one is a bit harder to explain, but I'd like to think the deactive ones were just baddly damaged.

It should be noted KRT and Fei'Yin still have colors associated with them, Cyan and Carmine. While Rang is listed as "Unlit", but this may be coincidence and it could be the "Gray Chip"... mistaken for unlit. On that note, this deepens a bit, during CoP, they added 3 chips.

http://www.ffxiah.com/item/1693/cyan-chip
http://www.ffxiah.com/item/1692/carmine-chip
http://www.ffxiah.com/item/1694/gray-chip

These are drops from enemies in CoP zones, and all correspond to the non-functioning Apparatus. Interesting, no?