Power Mac G4 Cube Bootup Issues

Hello

I recently have run into an issue where my Power Mac G4 Cube does not seem to bootup at all. Here’s all the details of what led up to this.

Firstly, I just got an Apple Studio Display (the 17” transparent one with ADC) for this G4 Cube. I plugged everything in to test the display, and it works beautifully. However, when the computer was booting up into Mac OS 9.1 on the first boot, it gave me a dialogue box that said something on the line of “The built-in hardware test detected a problem with the memory.” Please consult a professional or something. I just pressed continue as I figured that it wouldn’t bother anything. It booted up normally, so I played around with the machine for a few minutes. Then, by accident, I brushed the top of the G4 Cube with my hand to get dust off of it and touched the power button (I always forget it has a touch-sensing power button) which put the system in sleep mode.

I let it sit in sleep mode for a minute before I hit the spacebar to wake it back up, and this is where the issues seemed to have gotten worse. The thing didn’t want to wake up from sleep, so I did a hard shut-off. When I started it back up, all I got was a grey screen with a very thin black line about 2/3 of the way down from the top of the display, and nothing else. I did a hard shut-off again a few minutes later. On the next startup attempt, I got an error message that had a bomb icon, and the dialogue box read “Sorry, a system error occurred.” It had a two word description of what the error was, but I can’t remember it unfortunately. And in the box, there was only a “Restart” button. So I clicked restart, and then the same box appeared with the bomb and the “Sorry” message. I took a video this time, and this error said “illegal instruction,” which is definitely different from the first error message that it gave me. And there was only a restart button.

So then, I pressed restart again, and I got the same grey screen with the thin black line. At that point, I gave up, so I turned it off and started searching around. I tried removing and re-ordering the RAM sticks and trying different combinations (all of the modules are 512MB, but the previous owner seems to have gotten 3 different brands of RAM sticks weirdly). That didn’t work. 

I then tried resetting the PMU with the Cuda button. When I plugged it back in, the power button lights (on both the top of the G4 Cube and on the Studio Display) started flashing. It seemed like the flashing was in a pattern, since it would flash three times (not that rapidly, maybe something like 3 flashes per 1.5 seconds), then becoming solid, and flash three times and so on. Still no display. I turned the machine off after this attempt.

So, at this point, when I touch the power button, the lights light up as they always have, the hard drive spins up like it always has, and all of the other little mechanical noises that this machine has made since I got it 3 years ago come and go as they normally have, but that is about it. It doesn’t seem to be booting up into anything, there is no video. The Pro Mouse usually lights up at a certain point after the computer has been on for some time, but that doesn’t happen any more either. 

The last thing I tried doing was swapping the PRAM battery out. I put in a new one, but that still didn’t work. I did look through the top vent of the computer, and noticed at least 2 different lights on inside. I took pictures – one is red and on the left side, and there’s another one that’s green somewhere. I think I am seeing a 3rd red light somewhere, but I’m not sure. 

Now, I have a few things that I’m thinking could be the issue:

1. Could the Studio Display that I just plugged into this thing for the first time have caused some issue with the system? 

2. I have been keeping an eye on the hard drive on the G4 Cube, as it is quite loud. Did the hard drive just crap out?

3. Is the board fried, or is there some other catastrophic issue that killed it?

4. OR something else entirely?

Just some side info about this machine’s use that could be helpful:

I already had a 17” LCD Studio Display from a Power Mac G4 QuickSilver in my collection, so this display was shared between that and this G4 Cube. When I first got the computer, it had Mac OS X 10.4.11, and when I plugged it in, it would sometimes start up on its own without me even touching anything. I installed Mac OS 9.1 on it probably a few days later. Eventually, the random startup issues faded away. I didn’t use this very often, but it’s kept clean and whatnot. The last time I started it up was maybe two/three weeks ago (as of this posting), and it had no issues then. It has trouble ejecting discs from the top (but that seems to be an issue with most slot loading devices that are this old). 

The current specs of this G4 Cube:

450 MHz G4 processor, 1.5 GB RAM, 120GB HDD, ATI 128 graphics, CD-RW drive. 

Thanks for any help!

Wind5387