Scenario
Was able to get the read_key, but not the write_key:
[INFO] Starting the access key detection, please wait for many minutes...
[INFO] Detecting the read_key...
[INFO] Detected read_key: [75, 54].
[INFO] Detecting the serial number...
[INFO] Detected serial number "XB7R27****" at address 1604.
[NOTE] Current EEPROM value for the last byte of the serial number: 1613: 49.
[INFO] Detecting the write_key, do not power off the printer now...
[ERROR] Unable to detect the write key by validating against any of the known ones.

Maybe incompatible model?