Clevo W870CU (Sager NP8760) laptop own screen turns black when start-up Mountain Lion ( and Lion ).

[juha-68]

Hello all .

I post this this same message also "Laptop Compatibility " forun but unfortunately no results....

I have a strange problem with my Clevo w870cu laptop.
Hackintosh installation went fine ( and fast ) and I have install so far everything except Intel's built-in Wi-Fi card and onboard sound.
BUT here is the real problem ... Computer starts normally until it starts to load the operating system ( Mountain Lion ) from the ssd. Laptop screen turns black ( no singnal ? ) and nothing happens and I must shut down computer. The strangest thing is that, if laptop is connected start up to an external monitor DVI port there is no any kind of problem to start ( both displays will play without problems) . But when I shut down laptop and disconnect DVI to start again there is again black screen and no boot until I shut down again and connect DVI to start !

My own suspicion is directed to ati 5870m graphics card.

Does anyone have a similar problem and how you fixed the issue?

I hope someone has solution this problem. So help is needed...

Here is my laptop specs.

(CLEVO W870CU) 17"

Mainboard: Clevo P55 chipset
CPU: i7-920XM
GPU 5870M
Ram: 8 GB DDR 1333MHz
HD Intel ssd 180gig.
Optical drive: Blu-ray burner
Wlan: Intel 6300 Wi-Fi ( don´t work )
Bluetooth Model ???
Sound ( internal ???) ( Don´t work )

 

[praetorius]

try:

AtiConfig=Nomascus AtiPorts=2

 

[juha-68]

First of all many thanks that solution perhaps we are now right track ?
?
If I understand correctly (newbie) so I write that command Chimera boot screen ( I did ) ? Or os terminal ???

If so that don´t work . I also even try numbers 0,1,2,3 separately, of course .