Acer Aspire V3-731 Screen showing lines at bootup

Hi everyone. Forum Newbie here. Would really appreciate some advice here please....

I have an Acer Aspire V3-173, that when booting up, shows a black screen for the top 3/4, and lighter grey for the balance of the screen.
After a few seconds it changes to vertical lines and no further changes.
I have tested the connection to an external screen via the VGA port and this worked successfully.

I have removed both 4GB RAM, started with them one at a time, in different slots as well.

I have opened it, checked that the screen cable (on both sides : motherboard and behind the screen assembly) is correctly inserted and not damaged.

At the time of its failure, the laptop booted as normal and then changed to the black screen, without any changes for the better since then.

Aspire V3-731
Intel B970 2.3GHz cpu
Intel HD graphics
17.3" LEC LCD screen
8GB DDR3
1TB HDD
Windows 7 Home

https://www.dropbox.com/s/tinbu3pfgcce0j1/screen.jpg

 

if I get your problem right, the laptop's screen has the problem, but when you connect the laptop to a monitor, the problem goes away. If that is so, it;s not ram, it's the screen. Replacements are typically expensive, sometimes unobtainable, but look around, you might find one.

NOTE: Since no-one is there to troubleshoot your problem, there is a chance that my diagnosis is incorrect. Keep this in mind. If you had a replacement screen to try, (and you could return it if the screen was not the case) that would be the best way to test.