my iphone 5 won't connect to iTunes

I have same Problem for more than 6 months,I think the prob is with my iphone 5s ,cause my itunes on my imac will recognise every other iphone but mine will not,i have tried connecting to other computers but yet itunes will not recognise my device.I have reset the phone to factory setting yet no result,I am running lastest version of yosomite and latest version of itunes my iphone is also on 8.3.

Pls can some one help me!!!! A frustrated apple user

Hey so ive had this problem to i tried everything by updatingy pc and my itunes i finally figured it out i went on youtube an typed ITUNES DOSENT RECOGNIZE MY DEVICE [SOLVED] by ideviceblog follow those steps and i gurantee it will workk!!!!! im so happy right now i had to share it