When it arrives it starts with blackscreen and no sound. After i reball MCP79U its starts with white display. I notice that if i pres rapidly pwr key it starts with sound and after a while as it doesnt detect SSD an empty folder apear. With prw key rapidly pressed it boots from a installation usb all goes well till it cant find the ssd to insta OS. Please give me any advice if what i say does ring you any bell
Thanks in advance

Replace MCP79U with new chip

Not finding an SSD sounds like a BIOS-version problem to me. But as you're having more problems than that, you might want to solve those first :)

Look there: http://appleinsider.com/articles/09/02/ ... e_chipsets
All devices connected each other thru the one hub. If bios or operating system cannot communicate with one or more devices, that probably meen defect in MCP(Media Communications Processor)..
You have three different variants in this case:
1.) defect or broken MCP.
2.) defect or broken SSD.
3.) broken connection between MCP & SSD.
But, as you wrote:

I think it's mean a first variant :)
Reballing it's some kind of lottery.