Black Screen with MacPro 6,1 or iMac 15 or iMac 17 System Definition

[slim.jim]

When i set it up through Multibeast i chose Mac Pro 6,1

You should try other SMBIOS. If you are using a Skylake system, the most compatible is iMac17,1. If that one doesn't work the two with the least issues are MacPro3,1 and iMac14,2. You should only be using MacPro6,1 if you are running an X99 system.

 

[estebanpro]

how do i run the agdpfix is the screen is black. Help???

 

[slim.jim]

how do i run the agdpfix is the screen is black. Help???

Use the boot flag nv_disable=1 to boot and then run it.

 

[sterneborn]

I change the system definition to imac 12,2 and got blackscreen ... How to fix this? How to use the boot flag nv_disable=1?

 

[slim.jim]

I change the system definition to imac 12,2 and got blackscreen ... How to fix this? How to use the boot flag nv_disable=1?

You have something else going on or you didn't actually change your SMBIOS because iMac12,2 does not have the black screen issue. To use the nv_disable=1 boot flag go to Options at the Clover boot menu and then you will see the boot arguments a few lines down. Use your arrow keys to highlight that line, press enter, type in the boot flag and then press enter again. Return to the main boot menu and proceed booting.

 

[estebanpro]

Can I delete the folder 'KextBackUp" that appears on the desktop once I run the agdpfix.app?

 

[snowcamo]

I just bought a used Gigabyte Windforce GTX 780. I have tried using the adgpfix.app and I have tried using the clover patch. I even tried doing the ssdt injection (I'm not sure if I set mine up right in this case though) I still get a black screen. Any help would be greatly appreciated!

 

[el_charlie]

I have the same problem on my hack with iMac11,3 SMBIOS.

The weird part is that I'm typing this on 10.11.5 without problems, but I can't boot the El Capitan installer or the new Sierra PB installer (I get a blank screen and I know the installer is working). I can even boot to recovery just fine.

I tried renaming GFX0 to GFX1, GFX2, IGPU, PEX1 and no luck.

The weirder part is that on IOReg I see that the AppleGraphicsDevicePolicy is loaded and I have a working system. I upgraded via clover from Yosemite to El Capitan.

I can only boot to the installers using nv_disable=1. By using that flag I could upgrade to Sierra PB but as I rebooted, it will boot to a blank screen. The installation worked because I used Chrome Remote Desktop. Obviously with nv_disable=1 I can boot to Sierra, but without acceleration.

I don't know how I have a working system and I can boot to recovery, but I can't boot to the Sierra or El Cap installer.

I have a GTX 760 on a P55 board (iMac11,3)

PS: I don't want to change the system definition because I have working iMessage and Facetime.

 

[slim.jim]

I have the same problem on my hack with iMac11,3 SMBIOS

Your issues are different than this thread because this fix is specifically for the SMBIOS listed in the thread title.

Are you by chance using any VGA adapters?

PS: I don't want to change the system definition because I have working iMessage and Facetime.

System definition has nothing to do with working iMessage and FaceTime. I change mine all the time for testing.

 

[el_charlie]

Your issues are different than this thread because this fix is specifically for the SMBIOS listed in the thread title.

Are you by chance using any VGA adapters?



System definition has nothing to do with working iMessage and FaceTime. I change mine all the time for testing.

Thanks for your promptly reply.

I'm using DVI to HDMI cable or HDMI cable directly. No luck.

And I didn't know changing SMBIOS doesn't affect iMessage, but I still want to keep iMac11,3 because it matches my system almost perfectly (i5 760 processor and the chipset).

Like I said before, it's a weird problem I have. I can use OSX normally, boot to recovery, but I can't access either Sierra installer or El Capitan installer. Always blank screen. I know the installer continues working because I can hear the coils whining (my computer is old) and the activity light from the hard drive flashes.

I can use nv_disable=1 and even install Sierra, but I won't have any acceleration.

If I post my IOReg, DSDT and config here, can you take a look? I don't use Web drivers because my GTX 760 works OOB.

Another interesting bit. Looking at IOReg I see that AppleGraphicsDevicePolicy is loaded, no matter how I name the GPU (GFX1, IGPU, etc).

Thanks again.