At some point during my software updates and installs last week, I managed to get the video system on my MacBook Pro Mid-2014 to “get wonky”. That is a technical term, in case you are wondering.
“get wonky” – the point when something stops working correctly but is still almost functional. AKA “FUBAR Light”.
The issue only appeared on my external monitors on the displayport connections. The HDMI external monitor never had the flicker or “ants” issue.
After a couple of quick chat sessions with Apple Support the problem was resolved. I’m not sure what the source of the problem was but it was definitely software related. The software tests had passed and the problem did not exists for the first 48 hours that I owned the laptop.
I am fairly certain an SMC reset on the MacBook fixed the issue, but the 3 steps that were performed to get there are listed below. Hopefully this helps with your Mavericks video issues including both flicker (screen goes black as if turned off then back on) and “ants”, which apparently is Mac-community term for video pixelation artifacts that appear briefly as horizontal or vertical bars that quickly appear and disappear at random intervals. If you squint a bit while looking at your screen I guess it does sort of look like ants marching down the screen. Drinking a fifth of vodka before doing the squinty-eye technical assessment helps as well.
Here are the steps I used to fix my Mavericks video issue on the MacBook Pro:
Shut down the laptop.
Power on the laptop.
IMMEDIATELY press and hold the following keys, you must do this before the first gray screen appears:
Option + Command (⌘) + P + R
On the MacBook Pro Mid-2014 running Mavericks you reset the SMC by holding down these keys ON THE LAPTOP (not a USB keyboard) simultaneously for approximately 5 seconds:
Left-Shift + Control + Opt + Power Button
Login / Full Shutdown
When I powered on the laptop after doing these steps the video issue appeared to be WORSE.
Log in to your main admin user account, then shut down.
On reboot my problem was fixed.
Hopefully yours will be too.