I run a Mac Mini connected to two displays. The first is a DVI monitor (connected via a Thunderbolt to DVI adapter) and the second is a TV, directly hooked up to the HDMI out. I mirror the display to the TV to watch movies. The TV conked off a week back and was replaced.
The problem I'm facing after changing TV sets is, when I'm using the TV with the cable box or Playstation, the computer monitor starts blinking every few seconds, a solid black screen, similar to what one sees when changing resolution.
The blinking occurs twice about a second apart, every 15-20 seconds.
Observing the display options menu, I noticed that immediately after the first blink, the menu item for the TV disappears (because the Mac can't see it) there's another blink soon after when the TV gets detected and appears on the menu. It stays that way for 15-20 seconds and then the process repeats.
I've googled around and am at a total loss, I don't even know if the culprit is the Mac or the TV.
I've played around with the power consumption options on the TV, disabled mirroring, selected the "Use as separate display" option on the Mac - none of it made any difference.
When the display is being mirrored, it doesn't blink at all, steady on both ends, so I assume the HDMI cable (10 meters) is ok. Should I opt for a 5 meter high speed cable? Totally out of ideas, the only thing that works for sure right now is to pull out the HDMI cable from the Mac every time I'm not mirroring the display but that's a pain.
Edit: If I'm using the TV for Playstation or cable and power it off (standby), the monitor keeps blinking even when the TV is on standby.