HELP: Promox installed on MAC Mini from 2008, he doesn't boot any more..

[GoTraSYS]

Hello together,
I installed Proxmox 5.4 on my old MAC Mini from 2008 (newer verses didn't work).
The installation went fine, no error messages, but after the installation and the first reboot the monitor stayed black and nothing works anymore.
The Mac turns on, but no sound gong comes and the monitor stays black and nothing happens. I have tried all the known MAC keyboard combinations on the start, including holding the power button, nothing works anymore, seems like the MAC can't find the boot partition or the EFI of the MAC is corrupted....
Does anyone know how I can fix this?

 

[Richard]

Hello together,
I installed Proxmox 5.4 on my old MAC Mini from 2008 (newer verses didn't work).
The installation went fine, no error messages, but after the installation and the first reboot the monitor stayed black and nothing works anymore.
The Mac turns on, but no sound gong comes and the monitor stays black and nothing happens. I have tried all the known MAC keyboard combinations on the start, including holding the power button, nothing works anymore, seems like the MAC can't find the boot partition or the EFI of the MAC is corrupted....
Does anyone know how I can fix this?

Without knowing details about the mentioned physical machine: in such a case the nest step should be to examine the boot settings in BIOS, Proxmox can be also booted without EFi, therefore it's maybe the next step to allow legacy boot and define the disk where Proxmox was installed as 1st boot option.