Losing signal to my 2nd Viewsonic display, using a VGA to thunderbolt adapter.
I am using twin displays. primary is connected via VGA to HDMI adapter. The second is connected VGA to Thunderbolt adapter. Suddenly, my 2nd display, (connected via a VGA to Thunderbolt adapter), is periodically losing signal. The display flickers, and sometimes will act normally for a few minutes. I am using twin Viewsonice VA902B displays. This set up has worked properly in the past. I even purchased a new adapter, thinking the thunderbolt adapter became defective. Can anyone assist?
Running El Capitan 10.11.5 on a Mac Mini.
Mac mini, OS X Mountain Lion (10.8.5)
