shovelrider

I'm on the 520m and I am having the same issues with the screwed up screen. I had installed first using 10.9.0 and everything went OK. After updating through the app store to 10.9.5 the screen went haywire. So I made a new installer with 10.9.5 and with that the screen is even screwed up booting from the USB to do a new install. I've tried everything mentioned here that might be the problem with no changes. Any thought?