: Turn off the CK13i entirely and extract the battery for 5 seconds. Reinsert the battery but do not power the unit on. Press and hold the Volume Down or Sym/Space button, then plug the Micro-USB cable into the device.
Sony Ericsson Update Service (SEUS) (or alternative tools like Omnius for SE ) sony ericsson ck13i flash file z full
: Open your flashing tool (e.g., Omnius) and select the Go to product viewer dialog for this item. model from the list. : Turn off the CK13i entirely and extract