MP 1,1-5,1 Help with firmware update

[zibonst1]

Hello, I am trying to install a fresh OS (High Sierra) in recovery on my MP 5,1 late 2009. The OS install screen says I need a firmware update first and then explains how to do this (holding the power button, the tones, etc). When I do this it restarts and it doesn’t appear to have done anything. It just tries to boot to the drive, which has a faulty OS on it (which gives me the prohibitory symbol) which is why I’m trying just install a fresh OS. How can I get this firmware update installed so I can install a new OS thru recovery? Thanks!

 

[tonmischa]

Not sure if thats the reason for your trouble, but:
MacPro from "late 2009" is a MacPro4,1 (not 5,1). Latest OS for the MacPro4,1 is El Capitan 10.11.6. High Sierra is not (officially) supported.
I would try to install 10.11.6 from an USB bootable Install stick first and then go from there...

 

[zibonst1]

Not sure if thats the reason for your trouble, but:
MacPro from "late 2009" is a MacPro4,1 (not 5,1). Latest OS for the MacPro4,1 is El Capitan 10.11.6. High Sierra is not (officially) supported.
I would try to install 10.11.6 from an USB bootable Install stick first and then go from there...

Thanks for the reply. It’s was updated to 5,1. I’ve been running High Sierra for years on it. I installed an audio interface software on it and it wouldn’t reboot. So I’ve wiped it and done different Time Machine restores and also I have 2 external clones…all of which give me the prohibitory symbol since this happened. This is why I’m just trying to install a fresh Os. I have tried making and install usb using apples downloads and their terminal instructions but the thumb drives aren’t recognized for some reason. Thanks again.

 

[tsialex]

Read the first post of the sticky thread…

MacPro5,1: What you have to do to upgrade to Mojave (10.13/10.14 BootROM upgrades instructions thread)

Please fully read this first post, you will probably find that you have one or more problems described into the various notes below. Mojave will only install if you have upgraded your BootROM to the current release and your Mac Pro have a Metal capable GPU*. If you are trying to install Mojave...

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