[artlewis]

I locked myself out of an iMac (17" white frame) running 10.5.x after trying to install Linux Mint 9 (64 bit) and, sadly, after making that disc my startup disc (in System Preferences). The linux disc seemed to be doing an install but then informed me that the iMac wouldn't support the 64 bit install and ejected the disc.
The 'command line interface' says: "No bootable device ... insert boot disc and press any key", followed by a blinking cursor. There is no response though when any key is pressed.
I can't seem to get anything to boot the computer and that includes the 32 bit linux disc, my Snow Leopard disc, a safe boot, holding down the option key and holding down the 'c' key with Snow Leopard in the drive.
Any suggestions, because I'm not even sure there's an OSX installation on the hard drive?
Thanks,

[almaink]

Did you try reseting the PRAM? It should boot from the DVD if you hold down the C key. Holding down the x key will start any OSX install. Command + S key will start up into single user mode.
Compete list is here.
Mac OS X keyboard shortcuts

[artlewis]

Thanks, I tried each and every suggestion on the page - without any success. Same command line statement and prompt.
If it is not possible to get 'normal' access to the hard drive, is my only choice to replace the hard drive?

[P]

Odd. It may have messed up the boot blocks or something, but you should still be able to boot from a disc.

Try turning the machine completely off, and then pulling the plug. Press and hold the power button while plugging in the power cord. This resets the SMC, which shouldn't have anything to do with this, but it's an idea.

Exactly which model is this? Original Intel Core Duo?

[Waragainstsleep]

If your iMac is any of the models listed on these pages, you might be able to restore your firmware:

Firmware Restoration CD 1.4
Firmware Restoration CD 1.6
Firmware Restoration CD 1.7

Go for the most up to date version which matches your model.

[artlewis]

Thanks for the suggestions.

The computer is actually a 20" 2.4 GHz Core Duo (model A1224).

When I tried the suggested unplug and restart routine, I got a loud fan noise and a white screen, but no linux prompt.
Upon restart, it was back to the linux prompt.
I have swapped out the Apple mouse and keyboard for another Apple mouse and keyboard, with no effect.

I still have the Snow Leopard dvd in, although the computer can't seem to find or access the disc.
I'm out of ideas. I'm not quite ready to replace the hard drive, having looked over the 'how to' instructions.

Any thoughts?
Thanks.

[Cold Warrior]

did you try firmware restoration mentioned above?

[Waragainstsleep]

You want the 1.6 Firmware restore disc for that one. Actually it depends if yours is a mid 2007 unit or an early 2008. The Apple doc only lists the 2007 version but the 2008 is identical if memory serves. Its probably worth trying, even if yours is a 2008 version.

[artlewis]

Thanks Waragainstsleep and Cold Warrior, but it didn't work.

Since I never heard of or used Firmware Restoration, I'll just mention for others that you burn the firmware restore cd on a working computer and then can use it on the disabled computer. Very tidy idea.

I used the 1.6 (for the mid 2007 iMac) cd, but it wouldn't boot from the firmware restore disc. I got a rapidly blinking sleep LED and one long tone, but the computer still brought me to the linux prompt.

Very frustrating, but I appreciate all the help.
Surgery?

[Waragainstsleep]

Hang on. Looking back over the thread, you mention 17" with a white frame, then 20" 2.4GHz Core Duo. The earliest 2.4GHz was a Core 2 Duo in Aluminium. We need to check we are talking about the correct model, otherwise the firmware disc would not work.

The factory spec should be printed underneath the foot, or better yet post the serial number so we can correctly ID it. A1224 covers about 6 different iMacs. I don't know why Apple even bothers with the 'A' model numbers. The only ones which properly differentiate are only printed on the boxes.

Does it boot in firewire target mode?

[AKcrab]

People get freaky about serial numbers being posted online.. He should go to Apple - Support - Technical Specifications and put the serial number in and it will tell him the exact model for us.

[artlewis]

After putting the serial number into the Apple site, it's a mid-2007 (white) iMac, 2.4 GHz.
I used the Firmware Restoration version 1.6, which looks to be the correct one (iMac7,1).
Firewire Target mode doesn't work.
Thanks, Again.

[Waragainstsleep]

Yes, I have no idea why people get weird about their serial numbers being publicised. All they really tell you is the factory, year and week of manufacture, and exact model. Its not like I can steal your identity from it.

Moving on, I am going to assume that you can't tell white from silver because iMac 7,1 Mid [email protected] is aluminium.

Its starting to look like one of two issues:
1: Your HD is faulty. I cannot see how installing linux, or even failing to would prevent the various boot options from working so it could be a fault with the drive. I have seen that before.
2: Your firmware is screwed somehow. Again, I don't see why any install of linux would be stupid enough to try and modify firmware on a Mac, but target mode should work. As should startup manager.

Problem is, if your firmware is mashed and the restore disc doesn't work, then you are really out of luck. Apple will just quote you for a logic board.
It definitely looks like surgery time I'm afraid. disconnecting the internal SATA bus should suffice for testing purposes. If it is an aluminium model, take the glass panel out with suckers, undo the hex screws around the LCD and remove the memory door at the bottom. Once you get the alu frame off, you can disconnect the SATA cable at the logic board end which will save you removing the whole LCD assembly.
Try booting from DVD, target mode etc once you have disconnected the HDD. If that works, pull the drive and erase it. Then replace it and try again.

If you really do have a white iMac with no glass panel over the front of the screen, then your spec and your serial are wrong. This probably means that someone has swapped out the plastic insert in the foot with another iMac. Somehow. In which case, start trying the earlier firmware restore discs.

[artlewis]

Thanks.
I'll sort out what's what about the iMac and then try your suggestions over the Thanksgiving (US) holiday.
But, really, it's white - of that I'm certain.
I'll update on the results.
Have a good holiday.

[Waragainstsleep]

If its a white 20", then try Firmware 1.4 or 1.7.