I just updated to Mountain Lion and I have screen flickering on my second monitor. How do I get rid of the flickering? It seems to happen when I move a window around, or scroll on that screen.
Mac Pro, OS X Mountain Lion (10.8.1), Dual Apple 20" Cinema Displays
Had this on my iMac after updating to Mavericks, first i thought my Thunderbolt to DVI adapter was broken, but that was not the case.
The displays settings for the external Samsung monitor under older OSX used to show resolutions like 1920x1080 and 1600x900. After resetting everything it will query the external monitor and make a fresh table of supported resolutions, and in my case added 1080p and 720p (instead of 1920x1080 and 1280x720). Here are the steps i used (from memory).
Removed all custom colorsync profiles
Like /library/colorsync/profiles/S22B300 as well as from ~/library/colorsync/...
and also others like /system/library/colorsync/... if any.)
Removed /library/preferences/com.apple.windowserver.....
also from ~/library/preferences/byhost/com.apple.windowserver....
Zap PRAM (and choose startup disk)
Restart and hold CMD-ALT-P-R untill second startup chime.
(In case you have a different startup disk than the default one,
after the chime press ALT to choose your startup disk,
and set system-preferences startupdisk after boot.)
regards,
GDmac
If your display has an Ambient Light Sensor, some Users have gotten relief by turning that feature off.
After further testing. My LG W2343 has no problem,
but my Samsung S22B300B has huge problems.
It constantly goes on and off for some reason.
Apple, can it be some HDMI/DVI HDCP handshake problem?
You are NOT addressing Apple here. We are all just users like yourself.
To inform Apple, you do not get a response:
There is no "handshake" in HDMI or DVI. Like VGA, those "Legacy" protocols re-paint the screen with "heartbeat" regularity some 60 to 120 times a second.
HDCP is a protection protocol. Problems with that will give you no picture, period. It is active only at the start of playback. Once initiated successfully, the content will play all the way through without further checking.
Screen flickering on my second monitor
