Non functioning IMAC 5.1 after installing the wrong firmware

[Mackilla]

Hello

Joined as I have a problem. Have I killed my mac?

Have a mac 5.1, 20inch with 4gb ram. Downloaded a firmware update for another mac for A friends older 4.1 mac so that it would run the 5.1 firmware.

The file was run on the 5.1 and now the 5.1 no longer runs. When you press the power button the fan operate for a second then stop.

Tried resenting the smc by keeping the power button pressed, the resetting the PRAM with the keyboard on start even copied a dvdr to make the 4.1 firmware updater disc. So nothing happened.

Can I recover it?

 

[casperes1996]

If you can somehow get the firmware needed for your Mac, yes, you should be able to load that firmware back onto it. However, without a backup of your old one that may be an uphill battle.

 

[nambuccaheadsau]

Have a read of this link as you may have to use another Mac to burn a RestoratioN CD to achieve this.


https://eclecticlight.co/2017/04/26/startup-tones-efi-and-fixing-failed-firmware-updates/

 

[G4DPII]

So you downloaded Mac Pro firmware on an iMac?

This might be a stupid question. Why did the "friend" not just download the firmware on his 4.1?

 

[h9826790]

So you downloaded Mac Pro firmware on an iMac?

This might be a stupid question. Why did the "friend" not just download the firmware on his 4.1?

I think he mean the iMac 5,1 firmware, not the Mac Pro 5,1 firmware.

Coincidentally, both 4,1 can upgrade to 5,1 via firmware flashing.
[doublepost=1516612427][/doublepost]

Hello

Joined as I have a problem. Have I killed my mac?

Have a mac 5.1, 20inch with 4gb ram. Downloaded a firmware update for another mac for A friends older 4.1 mac so that it would run the 5.1 firmware.

The file was run on the 5.1 and now the 5.1 no longer runs. When you press the power button the fan operate for a second then stop.

Tried resenting the smc by keeping the power button pressed, the resetting the PRAM with the keyboard on start even copied a dvdr to make the 4.1 firmware updater disc. So nothing happened.

Can I recover it?

May I know if you mean you accidentally run the 3rd party "firmware tool" on your 5,1?

The Apple native 4,1 firmware updater won't accidentally run on a iMac 5,1. Also, a 5,1 firmware won't brick the 5,1.

However, if you run that 3rd party firmware too, it can downgrade your 5,1 to 4,1. And make a 5,1 can't boot because of the CPU now is not supported by the firmware. The solution is to install the 4,1 CPU on your Mac, let it boot, and use that same firmware tool to flash your "4,1" back to 5,1 again. Then you can re-install the original CPU back in.

I doubt if any Apple native firmware restoration CD can work. It it work, then every iMac 4,1 owner can upgrade their iMac to 5,1 just via the restoration CD. Why Netkas need to do some much work and release a tool for flashing? I think that CD can only restore the 4,1 firmware on your iMac now (because it is a 4,1 now), which won't help anything. But of course, nothing stop you to try. At least that's a possible solution.

 

[Mackilla]

So you downloaded Mac Pro firmware on an iMac?

This might be a stupid question. Why did the "friend" not just download the firmware on his 4.1?

The mac was with me and it was easier to download on mine and the use a USB flash drive to transfer the file that type in the wireless password.
[doublepost=1516655100][/doublepost]Do I have to use a cd rather than a dvd?

 

[h9826790]

Do I have to use a cd rather than a dvd?

Doesn't matter

 

[Mackilla]

Hello

I fixed it! Like to thank h9826790 for the idea, after looking at a cpu change idea, I thought I'd try replacing the memory back to 2 1gb chips. The IMAC is alive. Re ran the hack/patch and the mac is back as a 5.1. Replaced the memory back to 4gb and it is back to what it was.

Thank you all.