How can I download Sierra without the MAC working correctly?

You can try the SMC and PRAM reset first, since these are rather quick.  You also don't need to create a USB flash and can just use command r to boot from the recovery partition command  option r to boot from the internet recovery partition.

SMC reset:

• Unplug the Mac Pro.
• Press and hold the power button.
• Release.
• Then boot normally

PRAM reset

• Start the Mac Pro
• Press and hold
• command option p r

• Keep holding for 3 chimes. Newer Macs may not chime.  You may need to watch the screen for it to momentarily filcker 3 times.
• Release and let it continue to boot.

To upgrade to Sierra requires you have an installer disk.

State if you did a fresh install or attempted upgrading from an older OSX version.

If Sierra was not already "purchased" with your Apple ID account, you will not have access to download it.  You will only get Mojave now.

David Favor:   It is gong to be an upgrade from an older version that came with the computer.      

Serialband:  I don't believe Sierra was purchased at this time.   So Mojave is the only OS that can be downloaded now?

Likely good to answer why you're attempting to upgrade only to Sierra, rather than latest.

If you have a PowerPC chip, Sierra doesn't support PowerPC.

Start with why you're trying to install Sierra + if you actually have a Sierra Installer disk from Apple.

Does Mojave support the PowerPC chip?

No Mojave doesn't support PowerPC as hardware target for an OS install.

As I recall Tiger was the last OSX version to support the PowerPC chipset.

Best search through Apple docs about this.

Tip: Just try an install. If the Installer doesn't support PowerPC you'll get some sort of unsupported chipset message.

Tip: There use to be PowerPC emulators you could run some old OSX Apps on... which worked... with varying results..

Did pram reset, went furthur than before but now on black screen and white wheel stopped spinning with white cursor arrow flickering in upper left hand corner.  What now?   Any ideas?

Rebooted and back to original issue.   Can i just take,another mac and down load Sierra to a flash drive?    Reason for sierra is video card wont support mojave.

Just went through Apple docs.

Snow Leopard - last PowerPC support.

Lion - drops PowerPC support.

So, neither Sierra or Mojave has a chance to work on PowerPC hardware.

Snow Leopard (10.6.8) is the last Power PC version.  Do you have an old Power PC Mac?  The Sierra installer shouldn't have even been able to start on it.

Generally, if you "purchased" one of the older versions of OS X, you'll be able to download it, but otherwise you're going to get Mojave.  However, it does look like Sierra is still available for people to get, maybe because it's the last to use hfs+ as the default file system.  https://itunes.apple.com/us/app/macos-sierra/id1127487414?mt=12  from http://osxdaily.com/2016/09/20/macos-sierra-download-released/

This is not the usual case for other older versions of OS X.

Serialband, Can i down load to a flash drive?    Does ot have to be on another mac that I can get the download onto a flash drive, then boot from the flash drive on the troubled mac?.   Can i download to flash drive on a windows pc?

Best define "it", as there are many OSX versions discussed here.

Most of the OSX versions being discussed here were initially shipped on physical media, so they're unavailable for download from Apple.

For example, Snow Leopard shipped on physical media, so there there never was any Apple download version.

If you download them from elsewhere, you run the risk of installing Malware infected code.

Tip: Many times you can purchase old Installers off Amazon. Some can be pricy. Also make sure you actually receive an original Apple disk, rather than a copy, which an be infected with Malware.

The OS hoping to download is Sierra

You can stick an external SSD or HD and use it as a boot disk on any Mac.  USB memory sticks won't work.  Unfortunately, the download link goes to iTunes, and I believe it can only be downloaded from a Mac.  I've never used iTunes on Windows.


However, you should be able to just reinstall that Mac by going into recovery mode and start a recovery and just install the OS again.  It will restart the failed install and you should be able to continue from whatever caused the interruption.  You can even tell it to install on an external drive.  You won't be able to download the installer file for placing onto a USB memory stick until you've booted into a working OS X.  The download normally puts in the /Applications/ folder.

Tried tyo go to recovery Mode, but it also hung.

Then try the internet recovery mode.  (command option r during boot)  It's possible that your disk is corrupt at this moment.