MacOS Recovery boot not working

[PeteCsD]

Hi everyone, I have a MacPro 2009 (2x Xeon E5520, 64Gb ram 1022mhz ECC, amd Rx480) I wanted to do a DualOS, but boot camp is not supported on my Mac, I still managed to do it through Rufus, so, after I went to the system preferences and changed the boot drive from my Mojave to my Windows one, now I can’t go back to my MacOS, Cmd+R during booting doesn’t work, and booting pressing Alt seems to work, but my screen is black and doesn’t do anything, anyone knows a workaround for this? (I thought of removing the windows drive, this will show me "no boot drive insert CD/USB" on startup, and plug a Mojave Bootable usb and then either using the regular startup disk or a time machine I created before the whole DualOs, but I'd like a more permanent fix to make it easier go between the two OS)

[Ashleyyyy]

the alt key not working is a result of your aftermarket graphics card. you can still use it, just without a display output. what i mean is if you hold down alt, press an arrow key to select the other drive and then enter it'll work. 

[PeteCsD]

Just now, Ashley MLP Fangirl said:

the alt key not working is a result of your aftermarket graphics card. you can still use it, just without a display output. what i mean is if you hold down alt, press an arrow key to select the other drive and then enter it'll work. 

I tried 3 times, once I pressed the left arrow key, once only hit enter and the last one hitting first the arrow key to the right, none of this worked, the pc stayed on but the monitor stayed black, (I have an old macbook and tried the process just to doublecheck the interface and see if any other confirmation was required but no, it should boot up straight away into the drive).
Something else I thought about as well was to use the msconfig and change the bootdrive from windows, but unfortunately it doesn't show any other bootable drive, anyway I still appreciate you taking time of your day to help me out.

[Ashleyyyy]

1 minute ago, PeteCsD said:

I tried 3 times, once I pressed the left arrow key, once only hit enter and the last one hitting first the arrow key to the right, none of this worked, the pc stayed on but the monitor stayed black, (I have an old macbook and tried the process just to doublecheck the interface and see if any other confirmation was required but no, it should boot up straight away into the drive).
Something else I thought about as well was to use the msconfig and change the bootdrive from windows, but unfortunately it doesn't show any other bootable drive, anyway I still appreciate you taking time of your day to help me out.

i have a 2008 Mac Pro with an aftermarket graphics card, so i know the pain. 

 

what's odd is if you unplug the windows drive it doesn't boot. it should boot to the next available device but it doesn't seem to detect the macOS drive... can you explain that in more detail? maybe provide a picture of what it's displaying when you do that? 

[PeteCsD]

Just now, Ashley MLP Fangirl said:

i have a 2008 Mac Pro with an aftermarket graphics card, so i know the pain. 

 

what's odd is if you unplug the windows drive it doesn't boot. it should boot to the next available device but it doesn't seem to detect the macOS drive... can you explain that in more detail? maybe provide a picture of what it's displaying when you do that? 

now that you mention it I forgot to say that the main macOS is on a ssd, which is connected to a Sata to PCI-E card, I could try and mount the ssd onto the rail and plug it in straight in to the motherboard, although in future I'd like both system to ran on ssd to PCI-E as it gives me sata 3 specs rather than sata2, anyway attached is the boot image without the Windows HDD

[Ashleyyyy]

21 minutes ago, PeteCsD said:

now that you mention it I forgot to say that the main macOS is on a ssd, which is connected to a Sata to PCI-E card, I could try and mount the ssd onto the rail and plug it in straight in to the motherboard, although in future I'd like both system to ran on ssd to PCI-E as it gives me sata 3 specs rather than sata2, anyway attached is the boot image without the Windows HDD

ah. it's trying legacy mode for Windows for some reason, hence it fucks up. 

have you actually been able to boot into macOS at all? 

[PeteCsD]

16 minutes ago, Ashley MLP Fangirl said:

ah. it's trying legacy mode for Windows for some reason, hence it fucks up. 

have you actually been able to boot into macOS at all? 

not since I changed the startup disk

[Ashleyyyy]

20 minutes ago, PeteCsD said:

not since I changed the startup disk

that's bad... maybe try clearning PRAM, that should reset the startup disk. 

to do this, with the computer shutdown, hold down command, option/alt, p and r when booting, it'll bong, restart and bong again. once you hear the second bong release the keys, it should boot to macOS then, with the windows drive disconnected. 

[Ashleyyyy]

actually that could be a fix for this. if you want to boot macOS again just reset PRAM like that and it should default to macOS again. 

[PeteCsD]

1 hour ago, Ashley MLP Fangirl said:

actually that could be a fix for this. if you want to boot macOS again just reset PRAM like that and it should default to macOS again. 

worked perfectly, you just saved my non-exisisting music career ahahaha 
you reckon there's some more smooth ways? or that's as good as it gets?

[Ashleyyyy]

42 minutes ago, PeteCsD said:

worked perfectly, you just saved my non-exisisting music career ahahaha 
you reckon there's some more smooth ways? or that's as good as it gets?

sadly i doubt it, given that the Mac doesn't output the boot screen due to the gpu. still, this is much better than disconnecting drives etc as it should boot to macOS even with the Windows drive connected, since PRAM reset will simply reset the startup disk...