My Acer Aspire S7 displays only a line on touchscreen, but display works well when connected through HDMI.

[Dukes]

Acer Aspire S7 didnt have any problems till December 2014, Then it started flickering images and finally display an illuminous line near to one inch away from right side. When connected to HDMI to a TV, display is proper. Please suggest if this problem is related to anything to do with driver upgrades.

 

[jaguarskx]

Sounds like the display has failed.

You can replace the display yourself, but taking apart the laptop to do so is not for the feint of heart. And you need to research what screen is compatible with your laptop. Best to take it to a technician to fix the problem.