Mavericks hangs on Apple Boot Screen

[dichotomy2207]

GA-Z77X-UD5-TH 24GB 2xGT620. This machine has been running Mountain Lion without a burp for almost two years. I do indeed have 6 monitors -2 running of the mobo graphics and 2 running off each of the graphics cards. With Yosemite about to come out it was time to get the machine up to Mavericks. I ran the latest Unibeast to create a 10.9.5 USB. It works fine because I tried it on two of my other Hackintoshes (I have 7). It installs fine over top of ML and the first time I boot through the USB it comes up fine - all accounts, all files are fine. The network is not set up nor audio (as expected). I run Multibeast with no DSDT and do not specify audio yet (I can work around that later) and use the latest Intel network driver. After that, the system refuses to boot. I get the large Apple boot screen and the pinwheel underneath and it never finishes. If I re-install 10.9.5 I get one boot out of it and it hangs again. My USB has an LED on it so I can see that it is not being accessed. The light on the front panel stays off.

I am at wits end. I have uncabled the monitors on the Nvidia boards and disconnected all the USB devices except the keyboard and mouse. I have unplugged the other internal disk drives so only the one I am installing on is seen by the system.

I get exactly the same result if I try doing a clean install of 10.9.2

I'm sure the answer is obvious and I am just overlooking it because I have done so many Hackintoshes in the past.

 

[beelzebozo]

You should install with only 1 GPU installed.

I have an installation guide here: http://www.tonymacx86.com/340-snow-leopard-mountain-lion-ivy-bridge-installation-video-guide.html

You can skip to the UniBeast part.

 

[dichotomy2207]

Still no joy. I have tried it with both Nvidia boards, one Nvidia board and no Nvidia board. I always get the same result. The system is fine and bootable until I run MultiBeast. I have no choice because I need a network and audio.

I've tried PCIrootUID at 0 and at 1
I've tried GraphicEnabler at 0 and at 1

I have two disks on the machine, both Toshiba 2GB drives which are permission clean and have no file system problems according to disk utility. They both came from other machines and have flawless SMART histories.

I am beginning to lose my sanity over this.

I'd be happy to do a clean install on a blank disk but I can not get Migration Assistant to run to completion - it hangs with no message after about 3 hours.

This is my 9th Hackintosh so I'm not making (as far as I can tell) any newbie mistakes.

The computer ran ML for about 2 years with no problems so it does not appear to be a firmware issue. If I had to guess, there is something in /L/E or /S/L/E which is conflicting but I have no clue how to find it. The system has been upgraded from 10.0 up every time Apple comes out with a new release so who knows what might be lurking around.

Does anyone have any thoughts or suggestions ? This is getting me totally crazy.