Q: after jailbreak warranty lost or not

Apple does not support jailbroken phones as a rule

Unauthorized modification of iOS has been a major source of instability, disruption of services, and other issues - http://support.apple.com/kb/HT3743 - unauthorized modifications to the iOS (this hacking process is often called "jailbreaking").

https://discussions.apple.com/message/18970239 - Jailbreaking will void warranty, even after a restore if Apple can detect it having been jailbroken at some stage.