The format of the drives should not affect whether or not the computer can boot. I have a mix of HFS and APFS in a variety of Mac Pros and have no issues.Well I slid in my hfs hard drives into the extra bays and then the computer doesn’t start up because of that. Mojave is on a start up SSD.
OH, I didn't realize you were wanting them to boot! I thought you were using them as a data drive.hmmm I threw my old HD's in my newer mac and it wouldn't boot. I was thinking it was the drives but it might be the HD.
OH, I didn't realize you were wanting them to boot! I thought you were using them as a data drive.
You'll need to download the Mojave Installer from the App Store and target one of those drives if you want it to become bootable.
Actually, you’re not very clear about your objective at all. It’s hard to help until you clear up the factsActually no I have Mojave on a SSD as a boot drive. Now the issues might be actually my graphics card.
The drives are working now so it must just be the graphics card causing the problem.Actually, you’re not very clear about your objective at all. It’s hard to help until you clear up the facts
Is the Mojave boot SSD a pull from a different computer?
Are the HFS drives to be used as data only, and never booting?
What GPU is being used in both machines if the Mojave boot SSD was a working pull?
Please fill in the blanks. There may be even more information needed.