If a phone Navigation (Home, back, Recent task) keys does not work, then its definitely as a result of a bad touch screen(Calibrator) which will need to be changed and replaced with a new one, alternatively you can download and use third party button saviour apps like button saviour, home button etc, and use them for navigation for the time being,
To change and replace your faulty touch screen(Calibrator) you will need the service of an experienced phone repair engineer, you can click here to request for our phone repair service, because at Chrisrepair.com we offer swift and hassle free phone repair services.
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