Original post by: Jeff ,
Check the LCD connection to the main logic board, it is possible that there might be dust or an off connection causing your problem. Looking through the [guide|107939|teardown], I can’t help but notice the long LCD cable running right underneath the battery. It is very possible that this might be damaged from the battery replacement. Good news is, trying a [https://www.ebay.com/sch/i.html?_from=R40&_trksid=m570.l1313&_nkw=ZTE+ZMax+Pro+lcd&_sacat=0|replacement screen] isn’t that expensive.