Q: iphone 5s IOS 8.2can not back to itune on computer but my other ipad are ok pls hepl

Hi, Phạm Hưng. 

Thank you for visiting Apple Support Communities. 

I would need more information regarding what errors or issues you are experiencing when attempting to backup your iPhone to provide a better answer.  However, here is an article that may help resolve this issue. 

If you can't back up or restore your iPhone, iPad, or iPod using iTunes

Cheers,

Jason H.