Startup to "Open Firmware" Screen

Question

Level 1

8 points

Startup to "Open Firmware" Screen

I've used my iMac G3 without any trouble for 10 years. This week it began displaying the orange "welcome to open firmware" screen first thing on startup. I should mention that I'm currently running OS 10.4 on it and I believe I did the necessary firmware update prior to that and it has run reliably. I know the answer probably is contained somewhere on this forum--I searched and found a couple of fixes that haven't worked. I should mention that I'm able to boot up from a CD and have run Disk Warrior and TechTool Deluxe, both of which said things are okay.

So far I've reset the PRAM and done a couple of things mentioned dealing with NVRAM and resetting the defaults. Each time the computer restarts it comes up with the same orange screen. Any suggestions would be welcome. If possible, I'd like to avoid starting from scratch with the software.

Thanks,

John

iMac G3, Mac OS X (10.4.11)

Posted on Feb 21, 2010 9:43 PM

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Answer 1

rccharles

Level 6

13,037 points

Feb 22, 2010 9:53 AM in response to johnsnyder

From reading these posts, I get the feeling that going into openfirmware, could indicate a hardware problem. I'd try the things below, then consider trying a different harddrive or resetting the hd cables.

You can hold down the option key when you poweron your Mac. This will bring up a list of bootable devices/partitions. Click on the one you want then click on the arrow key. Also, you can press the return key to boot the highlighted partition.

Why set nvram variable? I've had open-firmware based Pegasos PPC and it simply had boot command, so instead of:

setenv boot-device ud:3,\:tbxi

should be enough to write:

boot ud:3,\:tbxi

Sometimes if volumes don't appear in Startup Manager (what you get when you hold down the Option key at startup), you need to reset the Mac's PRAM, NVRAM, and Open Firmware. Shut down the Mac, then power it up, and before the screen lights up, quickly hold down the Command, Option, P, and R keys, until the Mac has chimed twice more after the powerup chime. Then, before the screen lights up, hold down Command-Option-O-F until the Open Firmware screen appears. Then enter these lines, pressing Return after each one:

reset-nvram
set-defaults
reset-all

"The reset-all command should restart your Mac. If so, you have successfully reset the Open Firmware settings."
http://support.apple.com/kb/TS1812?viewlocale=en_US

How to eject a cd from the internal cd drive:
eject cd

List of devices:
devalias

List of variables:
printenv

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Answer 2

johnsnyder Author

Level 1

8 points

Feb 23, 2010 10:57 AM in response to rccharles

Thanks for taking the time to offer some possibilities--nothing has worked. Upon restarting it always came back to the open firmware screen. Finally, I decided to just erase the disc and reinstall the operating system starting with OS9 and then OSX. Thankfully, everything is running well again. I hardly know enough to speculate, but tend to thing some critical files were corrupted.

This leads me to a non-related question, but one that I've wondered about for some time. After reinstalling the operating systems from the original discs, I then updated OSX using Software Update, so everything on the computer was as supplied by Apple. Then, out of curiosity, I put in Disc Warrior just to see what the "graph" looked like. I expected it would be clean, but it reported that 28 percent of the files on the drive were out of order. This is odd to me since I hadn't used the computer for anything after the install. If I were to then run Disc Warrior and "rebuilt" things according to its method would that just mess things up and cause problems in the greater scheme of things--that is, contradict the order established by Apple?

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