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G4 Cube Sonnet 1.8 GHz no speed showing!

Akanthos

Akanthos

macrumors newbie
Original poster
Mar 8, 2016
8
1
Hi everyone,

I use a Power Mac G4 Cube, 1.8 GHz. It has a Sonnet CPU upgrade. I powered up the computer this afternoon and used the system profiler. There is this strange thing:
It shows that the processor is a 0 MHz PowerPC G4. I restarted the machine, but nothing changed. I wanted to reformat the hard disk and install Mac OS X Leopard, but when the installer loaded and prompted me to use a language to continue, the next message is that this operating system cannot be installed on this computer. This was the time I checked system profiler and saw this "0 MHz PowerPC G4" message.

Power On Self-Test:



Last Run: 7/24/16 6:03 PM

Result: Failed

Failure type: External cache

So, the external cache causes this. And every time it boots up, power on self test fails!!!
Can I do anything about it? Just hoping ...

:-[

Does any of you have any idea why this happens? I had a backup of my latest configuration with Leopard, and restored it from an image. But if I had no backup, I couldn't install Leopard!! So, this is a major problem. And I am afraid this could happen if I try to install an application.

Tried resetting the PRAM and pressed CUDA switch, but nothing happened!

I am waiting for any help on this ...


Spyros.
 
Last edited:
I agree-reset the PRAM.

Working on memory, the one in my Cube registers as a 1.8ghz 60? processor. I've not done a "clean" Leopard install on it, but don't recall having issues with similar upgrades with installing Leopard.
 
Either the firmware was not updated, or you need a cudda switch push, but most sonnet upgrades say upgrade the OS before upgrade not clean install.
 
havokalien said:
Either the firmware was not updated, or you need a cudda switch push, but most sonnet upgrades say upgrade the OS before upgrade not clean install.
Click to expand...

AFAIK, these particular upgrades won't boot at all without a firmware flash.

Although I own this exact combination, I didn't install it. With that said, I've installed my fair share of 7447A-based upgrades in PowerMac G4s, and the computers will not boot unless you've sucessfully flashed the firmware.
 
Some upgrades needed a special firmware for Mac OS X but need update only in OS9 so changing the cpu, it may work but not update correctly without correct firmware.

Seen it in towers mostly, but cubes seem even more finicky.
 
havokalien said:
Some upgrades needed a special firmware for Mac OS X but need update only in OS9 so changing the cpu, it may work but not update correctly without correct firmware.

Seen it in towers mostly, but cubes seem even more finicky.
Click to expand...

This particular Sonnet uses a 7447 processor. G4 PowerMacs WILL NOT boot with stock firmware with a 7447 installed. They will not chime, they will not post.

It has nothing to do with OS 9 or OS X booting-it's a matter of Open Firmware being able to work with the processor, something that-again-the stock firmware can't do.

A lot of lower speed upgrades use 745x processors. These are generally plug and play, although may need a firmware flash for the cache to work. If nothing else, though, the computer will boot with them installed. This is not true of 7447s(or 7448s for that matter). Processors that are 1.5ghz or faster are almost always 7447s or 7448s.
 
I had a first gen 450 cube that would not even take a 500 mhz processor from a later cube without the apple firmware, but I understand what your saying. Again it just seemed the cubes are more finicky.
 
Akanthos' Cube already has some non-stock firmware patch on it. If it didn't it wouldn't boot at all.
 
Thanks guys! My Cube was working well and the system profiler showed PowerPC G4 speed identification correctly. The "0 MHz PowerPC G4" message started showing a couple of days ago! I tried reseting the PRAM, I pressed the CUDA switch, but nothing seems to work. I am lucky that I had a backup of the Leopard configuration, otherwise I couldn't use the Cube at all !!

Though it's a little funny that my computer seems to have a 0 MHz G4 cpu, I 'd like this error message to be corrected! Anyway, I tried to install an application and it did install O.K. So I guess there will be no problems other than the -non capable to install OS-.
[doublepost=1469035336][/doublepost]I wonder if reinstalling the firmware update would fix the problem. And if it would, how can I do the firmware update?
 
Akanthos said:
Thanks guys! My Cube was working well and the system profiler showed PowerPC G4 speed identification correctly. The "0 MHz PowerPC G4" message started showing a couple of days ago! I tried reseting the PRAM, I pressed the CUDA switch, but nothing seems to work. I am lucky that I had a backup of the Leopard configuration, otherwise I couldn't use the Cube at all !!

Though it's a little funny that my computer seems to have a 0 MHz G4 cpu, I 'd like this error message to be corrected! Anyway, I tried to install an application and it did install O.K. So I guess there will be no problems other than the -non capable to install OS-.
[doublepost=1469035336][/doublepost]I wonder if reinstalling the firmware update would fix the problem. And if it would, how can I do the firmware update?
Click to expand...

It's definitely worth giving a try. You need to follow the instructions, but generally what you'll do is run the firmware update utility from the OS, shut down the computer, and restart it while holding down the programmer's button. On a Cube, this is on the bottom, so you'll want to start it with the computer on its side. If the firmware is successfully updating, the power button will likely flash rapidly and if you have speakers connected you'll most likely hear a long tone.

The last Sonnet I installed(dual 1.8) gave a magenta colored screen during the firmware update that showed the progress.
 
I read some instructions on a reference CD. Those are to install the firmware while the Cube is running OS 9. But this is not possible, as long as it cannot install the OS. I didn't know about the way you described.
Thank you for the information. I will do it and hope this will fix the problem! One more thing. Today I read the Diagnostics on System Profiler and this info shows up:

Power On Self-Test:



Last Run: 7/24/16 6:03 PM

Result: Failed

Failure type: External cache

So, the external cache causes this. And every time it boots up, power on self test fails!!!
Can I do anything about it? Just hoping ...

:-[
 
I bought a second hand cube. It runs fine. It also shows powerpc g4 0 mhz
There is a fan installed but i just can't find out what processor is installed.
Any tips?
 
If the CPU speed and cache size don't report correctly, then you have to actually look at it or run benchmarks to estimate its speed. Skidmarks GT should tell you the speed pretty accurately, and if you slide the cube out of the plastic chassis and take some pictures of the sides looking in, that might be enough for people here to identify the CPU card for you. If it has external power going to the card it's likely a Powerlogix/Newer Technology CPU.
 
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