Is macOS working ? If so, try installing refind from it.
Otherwise, the only solution I see is to take out the hard drive, and use another computer to install Linux in legacy mode (either you put the hard drive as the main drive of the other computer, or you put the hard drive in a USB enclosure to make it an external disk)
Linux Mint factory-reset on IMac
Forum rules
Before you post read how to get help. Topics in this forum are automatically closed 6 months after creation.
Before you post read how to get help. Topics in this forum are automatically closed 6 months after creation.
Re: Linux Mint factory-reset on IMac
Back to my originial post. Have you tried burning your .iso to a SMALL usb stick? By 'small', I mean an 8GB or less. Note in my post that I have attempted to boot some old macbooks with a 16 GB usb stick and it would not work--but boot worked with a smaller usb stick. I think the problem might be in the mac firmware that was installed with the last osx installed on the machines. Older mac firmware doesn't appear to recognize larger usb sticks, maybe because there weren't 16GB usb sticks available when the OS was released. It is definitely worth trying. Again, my experience is with macbooks, 2008 and newer, not imacs. Also, do not get hung up on a specific linux distribution. Although Mint is the best, sometimes another distro will actually work with an Apple 'out of the box', when ubuntu-based distros (such as Mint) will fail. Looking at your machine specs, I see no reason that linux will not install, providing there is no underlying hardware failure.
Re: Linux Mint factory-reset on IMac
There's been lot's of good advice here .
I have 3 of these machines or 5,1's to be precise which are basically the lower spec version of the 6,1 .
One I bought new and it failed very abruptly after 10 years of sterling service . One day it simply wouldn't post . The PSU apparently having burned out .
A few years later I was given 2 more and installed 64bit Mint 19 xfce on both . I used the Matt Gradient ISO downloaded from his site . I installed it via a DVD .
I tried installing via a USB drive but failed . Others have succeeded but I decided to just take the path of least resistance in this case .
Installation went well on one machine and I used it as a BOINC server for many months .
The second installation was finicky which I attributed to a failing DVD drive but eventually got it installed and also running BOINC . However I soon began to experience difficulties with it , more problems with the DVD player then crashes , freeze ups and failed boots . All very sporadic with no obvious pattern , sometimes it would work for days without incident but over time it just got worse and worse until it would always freeze during or not long after booting . I changed the DVD drive , the RAM , reset the PRAM and SMC dozens of times to no avail and eventually gave up . I never determined what the problem was although I'm pretty sure it was due to failing hardware . Most likely the PSU as reportedly this is a common point of failure on this model . These Macs are poorly ventilated yet suck up a lot of fine dust which is difficult to remove and perfect for cooking PSUs . Alternatively it might have been a failing motherboard . It is after all a 16 year old machine at this point !
So suffice to say you may well be experiencing erratic hardware problems whilst you are attempting to install an OS which from experience is quite exasperating and confounding . If you haven't lost all patience or interest at this point your best option might be to go back to the beginning and reinstall Snow Leopard with all it's most recent updates to get a solid idea as to the condition of the hardware . If it won't run OSX my guess would be you have a hardware issue , as you have mentioned you are even having issues with the DVD player now .
NB , I could boot and install Snow Leopard on the 5,1 from a USB and a DVD .
If you try to boot from an original OSX installation disk make sure it is the correct disk for your machine . Apple OS installation disks were often " keyed " to specific types of machines . So a Snow Leopard disk that came with a 5,1 might not work on a 6,1 because , you know .. Apple .
If I remember correctly ( perhaps not , this was some time ago ) I was able to boot from a 32bit antiX ISO on a USB drive .
As stated by Redog the size of the USB drive can be critical . 8GB seems to be optimal . Larger USB drives didn't work for me . Also which USB port I used on the computer made a difference . It seemed it only booted from a specific port ( I can't remember which . I found it by trial and error ) .
Good luck !
I have 3 of these machines or 5,1's to be precise which are basically the lower spec version of the 6,1 .
One I bought new and it failed very abruptly after 10 years of sterling service . One day it simply wouldn't post . The PSU apparently having burned out .
A few years later I was given 2 more and installed 64bit Mint 19 xfce on both . I used the Matt Gradient ISO downloaded from his site . I installed it via a DVD .
I tried installing via a USB drive but failed . Others have succeeded but I decided to just take the path of least resistance in this case .
Installation went well on one machine and I used it as a BOINC server for many months .
The second installation was finicky which I attributed to a failing DVD drive but eventually got it installed and also running BOINC . However I soon began to experience difficulties with it , more problems with the DVD player then crashes , freeze ups and failed boots . All very sporadic with no obvious pattern , sometimes it would work for days without incident but over time it just got worse and worse until it would always freeze during or not long after booting . I changed the DVD drive , the RAM , reset the PRAM and SMC dozens of times to no avail and eventually gave up . I never determined what the problem was although I'm pretty sure it was due to failing hardware . Most likely the PSU as reportedly this is a common point of failure on this model . These Macs are poorly ventilated yet suck up a lot of fine dust which is difficult to remove and perfect for cooking PSUs . Alternatively it might have been a failing motherboard . It is after all a 16 year old machine at this point !
So suffice to say you may well be experiencing erratic hardware problems whilst you are attempting to install an OS which from experience is quite exasperating and confounding . If you haven't lost all patience or interest at this point your best option might be to go back to the beginning and reinstall Snow Leopard with all it's most recent updates to get a solid idea as to the condition of the hardware . If it won't run OSX my guess would be you have a hardware issue , as you have mentioned you are even having issues with the DVD player now .
NB , I could boot and install Snow Leopard on the 5,1 from a USB and a DVD .
If you try to boot from an original OSX installation disk make sure it is the correct disk for your machine . Apple OS installation disks were often " keyed " to specific types of machines . So a Snow Leopard disk that came with a 5,1 might not work on a 6,1 because , you know .. Apple .
If I remember correctly ( perhaps not , this was some time ago ) I was able to boot from a 32bit antiX ISO on a USB drive .
As stated by Redog the size of the USB drive can be critical . 8GB seems to be optimal . Larger USB drives didn't work for me . Also which USB port I used on the computer made a difference . It seemed it only booted from a specific port ( I can't remember which . I found it by trial and error ) .
Good luck !