I have a Sony kd55x8509c android tv, I've had it just over a month now.
The setup is a sky hd box run to a hdmi splitter then one feed goes to the Sony and one to a Samsung tv
When both TVs are turned on the TVs display the same 1080i picture correctly, but if I put the Sony into standby mode the picture will stay ok,but every roughly 15 minutes the screen goes blank only for a split second then returns to normal then after a few seconds it does it again maybe once or twice. It then works ok for another 15 minutes but then the same cycle happens again. If I disconnect the hdmi lead from the Sony then fault does not occur.
If the Samsung tv is off and the Sony to is on the problem does not occur.
Before I got the android TV I had a lg and the Samsung and they works perfectly on the same system.
I can only put it down to the sony TV having activity on the hdmi port whilst in standby,is the same as when the device handshakes, it needs the hdmi routine to completely shut down until the TV is powered back on?

i have 3 hdmi splitters ( I've tried them all) and I can see by the LEDs on them that indeed it is the Sony hdmi port that's doing something whilst the TVs is in standby, the splitter shows the Sony seems to disconnect for a split second then reconnect thus the reason for a re handshake and this causes the Samsung to blank. 

I have rebooted the Sony and made sure it's the latest firmware, but no change. Google say it's a problem for Sony and Sony say to reboot the tv.