We need to determine whether it is a hardware or software issue..   Turn off the computer.   Tap f2 while turning on the computer.   It will go to bios.   Please stay on the bios screen for 30 mins.    If the display is looking good on bios then it is a software issue.   If the display is not looking good on the bios screen then it is a hardware issue.   

If it is a software issue try the following the steps..

Try windows x 
go to device manager 
expand display adapter
right click on display driver - uninstall 
Restart the computer 

It should work fine.. 

If it is still not working 
Uninstall the display adapter from device manager 
Don’t restart the computer. 
Go to support.acer.com 
chose your country 
type snid or chose your model 
go to drivers 
Install the display driver