Many people other then me have been having this problem.
What happens is upon launching the game it'll load up the program then go to a black screen(no signal found). It wont do anything further ,i am force to alt-tab open task manager and force end task.
Attempt(s) to fix -
Running both Steam and Arma 3 as administrator.
Using the verify integrity of game cache (through steam).
Reinstalling the game.
Unknown.
try startup parameter -winxp. It worked for me as I had the same problem.
https://community.bistudio.com/wiki/Arma2:_Startup_Parameters
I am currently having problems with the "99% download lag" on steam i will test when i can fix it and launch it.
BTW, you need to create a shortcut directly to the arma3.exe where you can include this startup parameter. Do not start arma via steam...
We need dxdiag and files from this folder to solve your problem.
C:\Users\<Name>\AppData\Local\Arma 3 Alpha\
i resolved it you can run it through windowed mode(through steam). once in game just change it to windowed full-screen.