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)

 

[pigoo3]

...but boot camp is not supported on my Mac

Boot Camp is definitely supported on your 2009 Mac Pro...but...is the issue due to the RX480 graphics card...or because you're running Mojave...or both. As I'm sure you know...these items are not officially supported...and thus may be the source of the Boot Camp issue.

, 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?

Command + R takes you to the Recovery Partition. Try pressing the Option key when booting to see if you get the choice to boot into the macOS install.

Also remember your screen may be "black" (at least initially)...because a non-officially supported video card is installed...which may not give you a boot startup screen.

(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)

Since you have a 2009 Mac Pro with 4 internal drive bays...another option could be...use one drive for a macOS install...and used a 2nd drive for a Windows install.

HTH,

Nick

p.s. Remember...your 2009 Mac Pro has a non-officially supported video card installed...and a not officially supported macOS install (Mojave). Thus you may run into unknown issues.