The Mac uses ONE display driver that is highly parameterized. The parameters are set in response to a query from the Mac that occurs only at certain times. The response from the display includes the display's Name and capabilities (what resolutions and frequencies are supported. If the display does not answer the query, the display is marked "not present" and it will not get serviced.
The problem most modern displays incur is that they have multiple inputs, and they tend to scan through their inputs over and over, looking for any signal. If the display is not paying attention to the computer-connected port, they could easily miss the Mac query, fail to respond to the query, and will remain dark.
Users have reported success if the display has internal settings to treat the computer connected input port specially, or exclusively, so that the display will look only to the computer-connected port, and will be able to respond when the query is sent and an answer is expected.
The query is only sent at certain times, including:
• at Startup
• on pressing the Option-(Detect Displays) button that appears in Displays Preferences when the Option button is held down (of course this can only apply to a second and subsequent display).
• at insertion of the Mac-end of the adapter or display cable
• at wake from Sleep
So another common work-around, to get the display to light, up is to sleep and wake your Mac.
