2011 imac can't seem to boot into anything except linux

[imacreuser]

Hey everyone, I'm hoping you can help.

I bought a used 2011 imac (12,2) for my son second hand, and I'm having trouble getting it working properly.

When I brought it home, it booted fine.. into Mojave.

I didn't know at the time but this is not normally supposed to work on such an old Mac. I noticed the wifi and the sound didn't work (as in the devices didn't seem to exist), and the boot drive had been replaced with an aftermarket SSD (too new to be original). Other than that it seemed fine. In any case, I wanted to wipe the hard drive.

I tried booting into recovery mode, but got an error when I tried to reinstall macOS. I think it just said something along the lines of "failed to install macOS".

I reset the NVRAM, which brought the boot chime back, but unfortunately I could no longer boot because it wouldn't allow me to boot into Mojave anymore, it would show the prohibitory symbol (circle with a line through it).

Internet recovery would download and then go to a solid grey screen. Regular recovery would show the prohibitory symbol.

I ran a livecd (usb) of ubuntu which seemed to be fine, and I wiped the internal SSD from there. I also enabled verbose boot mode in the nvram.

I got a osx 10.7 installer disk from a friend, but it also booted to a grey screen.

I tried installing macOS el capitan on an external drive from another mac, and booting from that. It boots to a grey screen (same in safe mode).

I also tried fully disconnecting the internal SSD. It didn't make any difference.

If I boot to the bootable usb el capitan installer, it doesn't go to the grey screen, it just reboots.

I've read about these macs having a bad GPU... but can that possibly be the case when Mojave (somehow) was running?

Any other suggestions?

Thank you

 

[BenAigen]

I don't know if this will help but I have a 2011 iMac that I use and runs on High Sierra (version 10.13.6) and runs very well.

 

[imacreuser]

I don't know if this will help but I have a 2011 iMac that I use and runs on High Sierra (version 10.13.6) and runs very well.

LOL thank you, that is really helpful. I'll go let my iMac know that he's not up to par with your iMac. I'm sure that will whip him right into shape!

Cheers

 

[Fishrrman]

OP:

What happens if you try booting to INTERNET recovery?
This is NOT THE SAME AS "the recovery partition".

Try:
Command-OPTION-R
at boot.

If you have a wired keyboard, that's what you should use.
Wireless keyboards... well, sometimes they don't work so well.

You didn't mention whether you're using ethernet or wifi, but if it's wifi, you'll need your wifi password.

The internet utilities take a while to load, be patient "as the globe spins".

This is a test. It is only a test. (as the old radio broadcasts went)
Try it, and let us know if you can "get that far".
If you can, it's possible to erase the ENTIRE internal drive, and start over, if you wish to.

 

[imacreuser]

OP:

What happens if you try booting to INTERNET recovery?
This is NOT THE SAME AS "the recovery partition".

Internet recovery would download and then go to a solid grey screen. Same result on wireless or ethernet.

If you have a wired keyboard, that's what you should use.
Wireless keyboards... well, sometimes they don't work so well.

I tried both. The keyboard never seemed to be an issue either way in terms of boot key combinations.

If you can, it's possible to erase the ENTIRE internal drive, and start over, if you wish to.

I tried erasing every partition, recreating the partition table, fully disconnecting the drive, none of them made any difference to how any type of booting worked.

 

[Fishrrman]

One other thing sticks out:
It's a 2011 iMac.
These were known for problems with dedicated GPU's going bad.

If the dedicated GPU is bad, I believe it can still boot from the integrated graphics in the CPU, but you have to have a bootable copy of the OS on the drive (and you erased that, right)? You would do this by holding down the shift key at boot.

Do you have access to ANOTHER, working Mac?

 

[imacreuser]

Please refer to my original post:

I tried installing macOS el capitan on an external drive from another mac, and booting from that. It boots to a grey screen (same in safe mode).

As for the integrated gpu, I'm not sure that's true in the case of these iMacs though. Not all i5s are equipped with intel graphics. Based on my research, that is the case with this gen of iMac (unlike the MBP of the same generation that had gpu issues but DID have integrated gpu).

 

[imacreuser]

SOLVED

 

[MikeG17901]

Google "OpenCore" and read about it. It is easy to use and maintain, and allows you to run unsupported Mac Operating Systems such as Ventura. The 2011 iMac can run Ventura with OpenCore, depending on RAM, and it will yield a good user experience. If interested, experiment; you can always restore to High Sierra if you do not like it.

Also, you can always bump up the RAM cheaply (ebay, amazon, etc.), which will allow it to run better on older machines. I have Ventura running on a 2014 Mac Mini with 4gb RAM, and a 2014 iMac with 8gb RAM.

Finally, you can easily install a SATA SSD (also cheap right now) for a further speed bump. There are many tutorials on YouTube and iFixIt.

 

[Fishrrman]

Well, tell us how you solved the problem...

 

[imacreuser]

First, I pulled the SSD and RAM out.

Then, I threw the iMac into a dumpster where it belongs.

Problem solved!