Referred to as “Touch Disease,” a hardware problem causes iPhone displays to become unresponsive and feature a thin gray flickering line along the top. This is the new concern for the iPhone manufacturer Apple. The design flaw, which causes the screen on the iPhone 6 and iPhone 6 Plus to flicker and become unresponsive, came to light last week after repair specialists said "a ton" of iPhone 6 Plus handsets have experienced the problem. The complaint filed in the U.S. District Court for Northern California alleges that Apple concealed the defect and has refused to fix it for customers.  "Apple has long been aware of the defective iPhones," the complaint says. "Yet, notwithstanding its longstanding knowledge of this design defect, Apple routinely has refused to repair the iPhones without charge when the defect manifests.

" The fault is apparently related to the touchscreen chip's connection to the iPhone's logic board, which can be compromised if the phone is bent - as some have experienced with the iPhone 6. Many customers who have brought the problem to Apple have been told the phones can't be fixed because the iPhone's one-year warranty has expired. “This action arises from Apple's concealment of a material design defect that causes the touchscreens on the iPhones to become unresponsive and fail for their essential purpose as smartphones,” the civil complaint contended. The lawsuit accused Apple of refusing to repair iPhones free of charge despite knowing that a design flaw was a fault.