me sale esto al intentar cambiar el CID:
C:\Android>fastboot oem writecid
..
INFO pyramid_init_sd, SD card po
INFOsdcc_init_memory_device done
INFO[FAT_ERROR] fat_open_file: c
INFO[JAVACARD_ERR] SMART_IO.CRD
OKAY [ 1.075s]
finished. total time: 1.077s
C:\Android>