I recently bought a certified pre- owned iPhone 5s from T-mobile. It looks very nice and everything works fine, except the touch screen will not work sometimes. It is frustrating to be texting, searching, calling, swiping, etc. when suddenly the screen just freezes and I have to reopen my phone each time. It happens consistently enough to be very noticeable and I have tried rebooting the device. What should I do?
iPhone 5s, iOS 8.4.1
See this support document regarding issues with the touchscreen. If the screen on your iPhone, iPad, or iPod touch doesn't respond to touch - Apple Support
You might also want to go to this site to see if you have any warranty left on the device and also check to see what T-Mobile says about warranty, in case you have an issue with the device. https://selfsolve.apple.com/agreementWarrantyDynamic.do
I'm also curious as to who certifies this device, and what they are trying to say when they say it is certified. You mention certified pre-owned, and I guess that can certify that someone else has owned it.
Take it to an Apple Store Genius Bar and have the technicians test it to see what is wrong.
What to do if touchscreen does not work sometimes
