iMac A1195 won't NVRAM/PRAM reset

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iMac A1195 won't NVRAM/PRAM reset

Hello!

I have a 2006 iMac "Core Duo" A1195. I was given this, and it had Windows 10 without Bootcamp, running natively. I cannot boot to recovery using Alt/Option + Command, and I heard that an NVRAM/PRAM reset will be able to make the iMac boot from macOS. I installed macOS on another Mac device of mine, and put the HDD in my iMac, and still have the, "No bootable device -- inset a boot disk and press any key" message rather than a blinking question mark, and I tried following this tutorial, and did press Alt/Option, Command, P, R and it just came back up with the, "No bootable device" error. I am still able to reset SMC, but I really need this iMac back on macOS as I plan to give this to my friend who really wants a computer who doesn't yet have one.

Thanks, and any help will be appreciated!

-Aiden

Earlier Mac models

Posted on Mar 18, 2023 9:30 AM

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Answer 1

Top-ranking reply

D.I. Johnson

Level 8

35,321 points

Mar 18, 2023 7:35 PM in response to I_Am_Aiden

The 2006 iMac cannot run any Mac OS version newer than 10.7.5 Lion.

What version did you install on the drive that you got from the other Mac?

It the drive was not formatted HFS+ (Mac OS Extended, Journaled) with OS X 10.4 Tiger, 10.5 Leopard, 10.6 Snow Leopard or 10.7 Lion installed, then the iMac will not be able to boot. There would be no bootable device.

This 2006 iMac had a bootable version of Window 10? Without Bootcamp?

Is it possible that Windows was hacked onto this Mac on a drive formatted with a FAT/exFAT and MBR partition scheme? If so, again, these are not compatible with a Mac startup drive.

The iMac shipped with a set of Mac OS X Reinstallation DVDs. They were specific to that model. Those disks can be use to reinstall the operating system.

If you don't have access to another Mac that can run an OS that is compatible with this iMac and allow you to install the OS on and external drive, then your other option will be to get hold of a set of the reinstall DVDs I mentioned above, or to find a retail version of Mac OS X Tiger, Leopard, Snow Leopard or Lion and use to install the OS.

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Answer 2

BDAqua

Level 10

250,259 points

Mar 18, 2023 12:04 PM in response to I_Am_Aiden

Does holding the Option key alone on startup show any boot choices?

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Answer 3

BDAqua

Level 10

250,259 points

Mar 18, 2023 5:43 PM in response to I_Am_Aiden

Yeah, that was what I needed, 1 long shot...

1.. Shut the machine down.

2.. UNPLUG the power lead to the computer and any peripheral devices.

3.. leave it for 10 minutes.

4.. Hold power Button in for 10 seconds

5.. Connect everything back up and restart.

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Answer 4

BDAqua

Level 10

250,259 points

Mar 18, 2023 2:49 PM in response to I_Am_Aiden

Just checking, this is using Wired USB KBs???

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Answer 5

I_Am_Aiden Author

Level 1

4 points

Mar 18, 2023 1:44 PM in response to BDAqua

Hi, BDAqua! Yes, I did try holding the Option key on multiple keyboards, and it just came back up to no bootable device. Also, when I try to reset the NVRAM/PRAM, it immediately goes through they grey screen and says no bootable device.

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Answer 6

I_Am_Aiden Author

Level 1

4 points

Mar 19, 2023 1:29 AM in response to D.I. Johnson

Hi, D.I. Johnson. I did install OS X Lion on the hard drive, and it was formatted with Mac OS Extended, Journaled. I believe that the hard drive used inside of the iMac was formatted with a different non-macOS device, as my brother gave this to me and isn't that big on Apple. I don't have any CDs, because then my brother told me that someone gave that to him, and I'm not sure why. I'm really not sure, because I had to use a different hard drive for this, as the original Windows 10 hard drive no longer works, and I was able to install Windows, but not macOS. I really have no idea how all of this happened, and I should be lucky that thing even works, as my brother told me it didn't work.

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Answer 7

I_Am_Aiden Author

Level 1

4 points

Mar 18, 2023 4:23 PM in response to BDAqua

Hello, I believe you mean a wired keyboard, and yes! I use a wired keyboard.

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Answer 8

I_Am_Aiden Author

Level 1

4 points

Mar 18, 2023 6:54 PM in response to BDAqua

Hello, I have tried this because I left the iMac sit unplugged for a bit longer and still nothing. I use a keyboard with a little light that lights up when its on, and it was definatly on...

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iMac A1195 won't NVRAM/PRAM reset

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