Grey screen with mouse after Apple Logo

[KuBuRG]

I have a problem when I try to run Mountain Lion setup from my usb key: after the Apple logo, it freezes on a grey screen with the mouse usable. I created the usb with unibeast from Virtualbox. How can I resolve this issue? Thanks
This is my pc:
Asus p8z68-v lx
Intel core i5 2500k
Xfx radeon HD 6970
Hd western digital 500gb
Ram 2x4gb 1600Mhz
LAN card and Audio card are onboard
Ps: sorry for my English, I'm Italian

 

[StarbucksSteve]

Grey screen on ML install ... OpenGL failure

If you look at the log, you'll see 'OpenGL xxx Channel Timeout!' messages. Try renaming the AppleGraphicsPowerManagement.kext in /S/L/E to ....kext.bak. This will leave your graphics chip at full speed all of the time - very responsive although for those attempting to maximize battery life somewhat counterproductive. The OpenGL failures are caused by the power management trying to find an acceptably lower-than-max speed for whatever task you are doing. I had issues from SL 10.6.3 thru Lion 10.7.3; 10.7.4 was very stable. Mountain Lion as well as Lion 10.7.5 are disasters in APGM ... removing it reduces my issues to annoyance level. KP's are gone and, although switching out of display sleep or screen-saver mode or hot-swapping a monitor can be somewhat slow, those functions do work without the AGPM.kext installed. I am running a Dell L702x with an nVidia GT 550M on a 3D display.

 

[Asus-Freak]

I have a problem when I try to run Mountain Lion setup from my usb key: after the Apple logo, it freezes on a grey screen with the mouse usable. I created the usb with unibeast from Virtualbox. How can I resolve this issue? Thanks
This is my pc:
Asus p8z68-v lx
Intel core i5 2500k
Xfx radeon HD 6970
Hd western digital 500gb
Ram 2x4gb 1600Mhz
LAN card and Audio card are onboard
Ps: sorry for my English, I'm Italian

If you got Unibeast off of Virtualbox who knows what you really have, and your screen freezes when trying to install because you're using an unsupported video card.

 

[roadrunner197069]

It is because your ati card, I have a 6850 and had the same issue. I deleted the ati6000kext from unibeast and it booted fine but then you need to manually reinstall the deleted ketx after you get it up- and running so make a backup of it. Details are on this page.http://www.tonymacx86.com/mountain-...ntain-lion-6xxx-gpu-issues-fix-inside-16.html

 

[MarcelBidon]

I have a problem when I try to run Mountain Lion setup from my usb key: after the Apple logo, it freezes on a grey screen with the mouse usable. I created the usb with unibeast from Virtualbox. How can I resolve this issue? Thanks
This is my pc:
Asus p8z68-v lx
Intel core i5 2500k
Xfx radeon HD 6970
Hd western digital 500gb
Ram 2x4gb 1600Mhz
LAN card and Audio card are onboard
Ps: sorry for my English, I'm Italian

This is probably the classical problem due to permission on HD6000 kext in installer.
This is conducting to a white screen with moving cursor at boot with most of HD6xxx card.
This might be your problem. This fix is working.
http://www.tonymacx86.com/mountain-...mountain-lion-6xxx-gpu-issues-fix-inside.html