Sorry for being stupid. I once thought 3GS cannot be jailbroken but after reading an article form iClarified http://www.iclarified.com/entry/index.php?enid=5432, I am confused. I have two 3GS phones: 1. Phone A was purchased in US from AT&T. I jailbroke and unlocked it with 3.1.2 before Apple refused signing firmware below 3.1.3. 2. Phone B was purchased local in Hong Kong. It is an unlocked phone i.e. no need to unlock because there is no "Apple-licensed operator in Hong Kong anymore. I also jailbroke it with 3.1.2 before Apple refused signing firmware below 3.1.3 My questions: 1. Phone A "died" yesterday suddenly and after some failed attempts of re-jailbreaking, it is now in recovery mode (yes i am stuck). Can I upgrade it to official 3.1.3 and jailbreak it? If so, how? It does not need to be unlocked because I am going to give it to a friend who lives in US and uses AT&T. 2. Phone B is working normally but I am scared it will die suddenly just like Phone A. Can I jailbreak it? 3. I saw this http://www.hackthatphone.com/3x/local_ecid_shsh.html and I want to "backup my SHSH and ECID". The instructions state I need to put Phone B to DFU mode but I worry it would screw my jailbroken 3.1.2. Would DFU mode screw it up and leave me an unjailbreakable phone? Many thanks.