iMac G3 wont boot

[sidewinder]

Sorry about yet another question...

We have some old iMacs, G3 Tray Loading, 333Mhz, 320MB RAM

Got one that would freeze when going into OS 9.1 so we used the only restore discs we had (which were 8.6) and all installed fine.

However now when it boots up it goes straight into command prompt with 'Apple iMac Open Firmware 3.0', a couple of copyright lines and then a prompt with "0 >"

Is it just not finding the HD to boot from? Or do we have to type something to get it to boot?

[petectid]

Its a long time since I dealt with Macs running pre OS X, but if I remember correctly the move from Os 8.6 into Os 9 required a firmware update. Therefore I suspect the firmware on your system is the wrong one for Os 8.6. You may find that you need to install Os 9 for this iMac to now work. All this from a distant memory, others may have a more recent experience than mine.

[GrumbleDook]

IIRC this is indicative of the PRAM battery starting to go. It can be replaced but takes some doing. Instructions are available one the Apple Support archives or on the tinterweb via google

[petectid]

Not quite sure about that Tony, when the PRAM battery fails the system makes all the correct startup chimes it often then fails to display any video output. What I suggested was that the firmware is wrong for the operating system, if Sidewinder types the command mac-boot at the Open Firmware prompt then if anything is going to work it will, the fact that it has started in Open Firmware would suggest to me that there is a fault that needs rectifying, not just the battery but maybe the firmware.

[GrumbleDook]

If it opens into Open Firmware and then you type BOOT, and it then starts up ... and you find that the time and date are wrong even though you have already set it ... then reset it correctly and restart the machine ...

It goes into Open Firmware again then type BOOT ... if the time and date are wrong again then it is the battery going (but not yet dead ... if it is dead then no display)

If it is not booting after that then it may be failing to find the hard drive after the install. If you boot from your CD and plug in an external drive you should be able to flash the Firmware to the last build available for that machine (it needs to be that for the 333MHz ... not the 350MHz .. there is a difference due the the 350MHz and above being able to see partitions larger than 8GB ... the Apple Support pages and Apple Discussion pages should have info on this but it is about 12 months since I last looked at PreOSX stuff!)

This link was the one I was thinking of with the battery issue though.

[petectid]

Tony does the question say anything about the Date being wrong or even printers selected in the Chooser disappearing, classic symptoms of PRAM battery failure? The system is booting into Open Firmware, as you mention the iMac in question shipped with Firmware that did not support drive partitions greater than 8Gb.
Sidewinder is your drive larger than 8Gb if so you will need to partition the drive so that the first partition is smaller than 8Gb install your system on this. If your Firmware has been updated to support larger drives then your problem lies elsewhere. If you need to update the Firmware for your iMac you will find it here, though I have never done this to a Mac that does not boot, Tony gives an example of how you could do this from an external drive, I've never seen this method documented by Apple.

[GrumbleDook]

Tony does the question say anything about the Date being wrong or even printers selected in the Chooser disappearing, classic symptoms of PRAM battery failure? The system is booting into Open Firmware, as you mention the iMac in question shipped with Firmware that did not support drive partitions greater than 8Gb.

I didn't think it was booting from the internal drive at all .. just getting to Open Firmware ... that is why I gave instructions about how to boot into it and what else to look for ... and why I also gave other possiblilities ... without actually looking at the machine there could be a few other problems. I have seen similar with a partially knackered drive cable (but this was after it had been taken apart and put together again and the cable crushed), a short on the board (dry solder joint on the power board ... replaced powerboard sorted it) but these come with other symptons ... none of which can really be seen until the machine is booted and other utils run (if you have OS9 then get hold of an old TechTools Pro CD ... a blessing!)

Sidewinder is your drive larger than 8Gb if so you will need to partition the drive so that the first partition is smaller than 8Gb install your system on this. If your Firmware has been updated to support larger drives then your problem lies elsewhere. If you need to update the Firmware for your iMac you will find it here, though I have never done this to a Mac that does not boot, Tony gives an example of how you could do this from an external drive, I've never seen this method documented by Apple.

I used to have a system image of these machines loaded onto an external drive ... I used to boot from an OS 9 CD and reload the image onto it when connected via USB (USB 1.1) ... talk about slow!!! The loss of the external SCSI port to boot from was a great loss on early iMacs and the advent of Firewire was the point when they became easily manageable.

[petectid]

There could also be a problem with the NVRAM you could reset this by typing reset-nvram at the Open Firmware prompt or reset-all. The later will reset all the Open Firmware settings and restart the iMac.

[sidewinder]

I think it was the firmware issue after all

Installing OSX now so will see what happens when it finishes

[sidewinder]

Installed fine

Thanks guys