Please help me get my Mac Pro back to life after attempted OSX reinstall

[matyw]

Hello,

In preparation of selling a 2008 Mac Pro (with 3gb flashed video card) I was trying to wipe it clean and put a fresh install of the OS on the computer. I couldn't figure out how to do this by following the common instructions online and missing the good old days of popping in a disk.



I can't remember exactly what OS it was on but I had the current FCPX, Motion etc working great.



I formatted the SSD properly and kept getting the error that the service was temporarily unavailable with the recovery mode and trying to install "Sierra".



So I plugged in the SSD to my MacBook Pro and re formatted and even reinstalled Sierra there. That didn't agree with the Mac Pro so I reformatted again and tried the recovery mode on the Mac Pro again and that no longer worked. I just kept getting a circle with a line through it. After much cursing I suspected that my flashed 3GB video card may be the problem. So I put in the old 7300 and now nothing. I can't even get the circle and line back on the screen. Granted I changed the cable now and also the card. More cursing!



Any advice on where to start this process will be helpful before I smash to bits.



Many Thanks for reading,

Matt

 

[Filin]

1. 2008 MacPro does not support Sierra (without modification)
2. You need to download 10.11 to your MacBook and make bootable usb flash drive. Use this usb drive to install clean system on your MacPro

 

[matyw]

1. 2008 MacPro does not support Sierra (without modification)
2. You need to download 10.11 to your MacBook and make bootable usb flash drive. Use this usb drive to install clean system on your MacPro

Thank you, Thank you! I am downloading 10.11.4 now to see if I can get this going.
[doublepost=1490042393][/doublepost]The El Capitan version I downloaded seems to be good but it gives an error that it is too old to be opened on this computer.

 

[Filin]

The El Capitan version I downloaded seems to be good but it gives an error that it is too old to be opened on this computer.

Not sure that understood you correctly. On what stage you got this error?
Or you trying open 10.11 installer on your MacBook?

P.S. You dont need to run 10.11 installer on MacBook. You only need to download it and make bootable USB follow instruction http://osxdaily.com/2015/09/30/create-os-x-el-capitan-boot-install-drive/

 

[matyw]

I got it sorted. I used an older Mac that was still on El Capitan to install the external bootable OS.
Many Thanks for your help!