• Updated 2023-07-12: Hello, Guest! Welcome back, and be sure to check out this follow-up post about our outage a week or so ago.

Mac Mini G4 - prolonged gray screen, USB devices doesn't seem to work on startup

Kurasiu

Member
I recently picked up a G4 Mac Mini (1.42 GHz) model, with MorphOS installed on the hard drive. Since I wanted to try running the Mac Mini 9.2.2 v9 from macos9lives, I cleaned it up, removed the drive and formatted it on another Mac and finally burned the CD with the modified OS 9.

However, everything went downhill from there - after putting everything together, the Mac Mini stays on the gray screen for around 3 minutes, and them immediately starts flashing the question mark folder - it doesn't even attempt to boot the CD. What's worse, I also found out that the USB keyboard and mouse doesn't work, so I can't even eject the CD, zap the PRAM, or boot into open firmware (when I ran the previous installation of MorphOS, the mouse and keyboard worked just fine, so no idea what happened there).

Any idea how to salvage this one? Will an official USB Mac keyboard and mouse from the era solve the issue?

 
Last edited by a moderator:

ArmorAlley

Well-known member
I recently picked up a G4 Mac Mini (1.42 GHz) model, with MorphOS installed on the hard drive. Since I wanted to try running the Mac Mini 9.2.2 v9 from macos9lives, I cleaned it up, removed the drive and formatted it on another Mac and finally burned the CD with the modified OS 9.

However, everything went downhill from there - after putting everything together, the Mac Mini stays on the gray screen for around 3 minutes, and them immediately starts flashing the question mark folder - it doesn't even attempt to boot the CD. What's worse, I also found out that the USB keyboard and mouse doesn't work, so I can't even eject the CD, zap the PRAM, or boot into open firmware (when I ran the previous installation of MorphOS, the mouse and keyboard worked just fine, so no idea what happened there).

Any idea how to salvage this one? Will an official USB Mac keyboard and mouse from the era solve the issue?
I've installed Mac OS 9.2.2 using the image from MacOS9Lives onto 6 mac mini G4s. I only had difficulty with one of them. It seems that the DVD-drive in that machine is defective.

I got around around my problem by attaching an external firewire DVD-burner and booting from a newly burned boot CD. I assume that you put the newly formatted hard-drive back into the mac mini G4. (It's a silly question but I ask since you didn't mention it.)

For all of the machines (including the one that I booted from the external drive), I pressed C at startup and held it there until I saw the familar smiling mac.

Does nothing happen when you press Command-Option-O-F at startup?

I found this site helpful when I was diagnosing problems: https://www.osxbook.com/book/bonus/ancient/whatismacosx/arch_boot.html

This section seems relevant to you:

If Open Firmware fails to find a boot device, a blinking folder is displayed.

Open Firmware then loads a file of type tbxi (ToolBox ROM Image, for historical reasons) from the system partition. Note that this would have been the file called "Mac OS ROM" in the System Folder on Mac OS 9, while OS X loads /System/Library/CoreServices/BootX, which is the bootloader as well. BootX is then executed and Control is then passed to it.

Another has come to mind: your mac mini G4 supports target mode. I've never tried it without an OS but I think it is supported by OF so it may work.

 
Last edited by a moderator:

Kurasiu

Member
Thanks! I've actually managed to get the OS9 up and running, by pluggin the drive to the other Mac I have, and running the Apple Restore Utility... I have no idea why I haven't thought of that before. :)

However I encountered a more severe problem - the Mini, completely out of the blue, stopped working. It literally appears dead. I just powered it off, and later when I wanted to power it on, absolutely nothing happened. No HDD activity, no chime, no video, not even the LED lights up. At first I thought it's the power supply, but I did get some readings out of it (my probing cables have a tad thick tip, I couldn't properly measure it) - I tried different outlets, cables and even probed the motherboard (I couldn't find the pinout, but one of the power supply connector legs seems to be getting the +18V power, but nothing on the rest...). Did the power supply just died on me, or is the motherboard toast for some reason?

 
Last edited by a moderator:

Kurasiu

Member
Well rats, sorry for double post, but looks like this thing's totally dead. I borrowed a working 85W (18V/4A) Mac Mini power supply, and no reaction whatsoever... I had a 110W one, supposedly fully compatible, with an output of 18V and 6A - maybe that slowly cooked it to death?

 

ArmorAlley

Well-known member
Well rats, sorry for double post, but looks like this thing's totally dead. I borrowed a working 85W (18V/4A) Mac Mini power supply, and no reaction whatsoever... I had a 110W one, supposedly fully compatible, with an output of 18V and 6A - maybe that slowly cooked it to death?
How easy are mac mini G4s to recap?

 

Daniël

Well-known member
Well rats, sorry for double post, but looks like this thing's totally dead. I borrowed a working 85W (18V/4A) Mac Mini power supply, and no reaction whatsoever... I had a 110W one, supposedly fully compatible, with an output of 18V and 6A - maybe that slowly cooked it to death?
Probably not, a modern device will only draw as much amperage as it needs. As long as the voltage is 18V, and the amperage is at least 4A, it'll be fine. It just won't draw the full 6A on the 110W adapter.

 

Kurasiu

Member
I found yet another Mac Mini locally (although it's the 1,2GHz variant), and what a neat surprise - everything works like a charm, keyboard during the boot, booting from CD and such! At this point I wonder if that older Mini was already on the brink of death when it was still (somewhat) working...

 

ppcoutlaw

Active member
Well, here is my two cents worth on your dead mini. I was about to suggest that you try a different drive to see if it was a HD data cable issue. I had one go bad once, just how I do not know. It's just wires, right? Ha. The drive was good, just as yours is, and the machine worked fine until I changed the drive. After hair pulling for a few minutes, I discovered the cable had died. Probably a really thin copper line had been pinched at some point and it broke with the extra movement when I hooked up the drive.

As for the power supply killing the machine, it is possible if the machine has a weak component somewhere along the power path. I had a reverse version of that with a bad battery for an electric drill killing my chargers. I had three batteries, and two were just fine. The bad battery worked in the drill ok, and it charged ok, but I went through three chargers before figuring it out that one of the three batteries was a killer. It melted the innards of the last charger. That was the clue for me as to what was happening. Sorry to see it was a 1.42 that died on you. They are pretty nifty boxes

 

adespoton

Well-known member
Having opened up a number of 1.42 G4s... you might want to check that your power button connector is not damaged and is solidly connected to the mainboard.  I've had a couple of "uhoh" moments when putting everything back together and realizing I forgot to plug that connector back in.  I can't see any reason for there being absolutely no response when a power supply is in and you press that button, other than that the button isn't signalling the board properly.

If you power it up with the top not fully on, there's an LED on the left side from the back that should light up if power is getting to the mainboard.  If this doesn't light up, it's your power button at fault.

Your previous issues with the long boot sound like it had a lot of potential bootloaders to scan through, but none of them were configured correctly for boot.  The restore overwrote the partitions such that OF was able to find the Apple Boot partition, which sped up the process of finding the correct tbxi on the correct partition.

Good luck!  I love my 1.43 G4s; they've been workhorses for me.

 
Top