[macman247]

Thanks for clicking on this post. Please hear me out...

I bought a used PowerMac G4 Cube and Apple Studio Display (17" ADC) from a customer about a year ago, and has been a wonderful and stable until recently... I've purchased quite a few upgrades to it since I purchased it:
(in order)
120 GB WD SE HD, additional 512 MB RAM, CubePort, GeForce 3 64 MB, AirPort, iSight, iPod, a refurbished 20" Cinema Display, PowerLogix 7457 1.2 Ghz, and a M-Audio Transit.

The deflection board on my 17" ADC Studio Display went out, the picture squeezed horizontally and almost started smoking, but I chalked that up to continuous use and old age as I have seen that happen before on other customer's monitors, and used that opportunity to get a flat panel.

Ever since I had my iPod and AirPort, I've notice that if I was playing any audio as I transfered files TO the iPod (but oddly not FROM) or share Ethernet via AirPort to my PowerBook, i would get some static on the 45W amplifier/speakers that came with the Cube. Sometimes it would get bad to the point where they speakers would remain at a soft volume and i'd have to unplug them and plug them back in to regain full volume. A few times it would kill the whole USB bus until i slept/shutdown. That happened rarely and thus only a minor nuisance.

Now with the Transit USB audio device (connected straight to the logic board), a similar static noise will occur when performing said tasks, and will eventually cut off all sound with no hope of regaining it back. The device's power light remains on. If I don't restart after an hour or so after that happens, I will usually get a kernel panic. Sometimes applications will refuse to quit, or will quit, but retain a place on the dock, yet have no pid in Terminal/Activity Monitor. Upon further inspection, i noticed that the kernel_task was taking up all free CPU cycles, and thus explaining the erratic behavior of the dock and refusal to sleep correctly or re-initialize the Transit. System Profiler show the Transit still connected even if it's removed, and USB Prober (from Developer Tools) will refuse to launch.

In my few years working at an Apple Specialist I've never seen anything like this! It can't be the processor, because it's happened with the stock and upgrade. It can't be the monitor because I've replaced that. I doubt it's the video card or hard drive, as those have been replaced with newer parts (although I haven't tried swapping the old ones back in yet). I've tried reseating/removing the AirPort card and CubePort internal modem replacement to no avail. Unplugging the iSight doesn't help, I have a zip 650 CD and hp PSC 2110 running off a small un-powered hub (both devices require power from the wall anyways) and have tried disconnecting those as well. It could be the OS i guess, but i think i've done a clean install in the past when the problem existed. It seems like there is some sort of interference caused by something loose or not grounded correctly internally (but nothing seems out of place or missing on initial inspection) or something is causing the USB bus to be strained so much that it can't sustain the correct power or transfer output and then things cascade from there.

I was thinking it could be problems with power, but the 7457 and Cinema both take considerably less power than what they replaced. However, the GeForce 3 and 120 GB hard drive probably take a little bit more. I'm thinking either a bad logic board, DC-DC board, or power brick. Hopefully it's not the GeForce 3, I paid a mint for that!

Has anyone had any problems even remotely similar to what I've described?! What exactly would happen if the DC-DC board was bad or going bad and what components does it power directly? Please any suggestions! Let me know if i need to clarify my post or troubleshooting process here. Thanks in advance...

[Sophus]

Originally posted by macman247:
Ever since I had my iPod and AirPort, I've notice that if I was playing any audio as I transfered files TO the iPod (but oddly not FROM) or share Ethernet via AirPort to my PowerBook, i would get some static on the 45W amplifier/speakers that came with the Cube. Sometimes it would get bad to the point where they speakers would remain at a soft volume and i'd have to unplug them and plug them back in to regain full volume. A few times it would kill the whole USB bus until i slept/shutdown. That happened rarely and thus only a minor nuisance.

I was thinking it could be problems with power, but the 7457 and Cinema both take considerably less power than what they replaced. However, the GeForce 3 and 120 GB hard drive probably take a little bit more. I'm thinking either a bad logic board, DC-DC board, or power brick. Hopefully it's not the GeForce 3, I paid a mint for that!

Has anyone had any problems even remotely similar to what I've described?! What exactly would happen if the DC-DC board was bad or going bad and what components does it power directly? Please any suggestions! Let me know if i need to clarify my post or troubleshooting process here. Thanks in advance...

Hi,
I have the exact same problem with my Cube G4, 1Ghz Powerlogix, 120GB Seagate Barracuda, OEM Radeon, Airport, iSight and iPod dock connected.

I have not experienced the kernel panic though. But the fix is, as you have mentioned, usually reboot or unplug and then plug the speakers back in.

I have spent quite a few hours trying to track down this extremely annoying problem. At first I suspected that lack of power might be the problem, since I experienced cracking and popping sounds, and then a muting of the volume to about 1/3 of the normal level, like there was to little power on the USB bus to drive the speakers properly. I still don't think it is directly power related though.

I also, thought it might be related with a "hanging process", or the CPU peaking, but top/system monitor shows nothing wrong, though since reading only at intervals, the report may not show the whole picture (micro peaking on the CPU).

I rebuilt my disk with diskwarrior, fixing a "bitmap error" or something like that, which helped for a while, though this may have been a coincident. It might be a kernel task hanging on accessing the problematic disk, though this is also just a theory.

I am interested in solving this. Let me know if I can help you in any way. Any other cubeowners with similar experiences?

Sophus

[Sophus]

Ok, I will resurrect this old thread.

I still have the problem with my Cube.I have searched the Cubeowner forums and discovered that we are not alone, far from it. Almost all threads in the USB/Firewire/Audio forum is dedicated to this problem.

If my memory serves me right, the problem started with late OSX 10.2, or possibly with 10.3. I have also discovered that when the problem occurs, this is logged in the system log:

"Jan 27 22:14:35 localhost kernel: USBF: 2824.297 AppleUSBOHCI[0x1b1e000] Watchdog detected dead controller (hcca #: 298, hc #: 1005)"

(Often 10-30 times in a row). It seems to occur when there is Airport or firewire activity. Somtimes the volume is not only muted, but the port is dead. A shutdown, restart brings it all back to normal, untill next time I play music and access airport or firewire.

Since it happens also with people with stock CPUs I am now less sure that it is power releated. I am more amd ,ore suspecting driver issues.

If you own a cube, please chime in and let me know if you exerience the problems, and let me know your configuration i.e. Airport, firewire, CPU upgrades etc.

I have been contemplating on getting the new Gigadesigns VRM with better capacity, but will hold off to see other cubeowners experiences first. If you get, or got a Giga VRM, please let me know about your experiences.

The problem is really annoying, and worth $99 to get it fixed.

Cheers,

Sophus

[Link]

Wow I can't believe this bug still exists!

Way back in the OS 10.1 days, there was a bug with the USB audio driver (specifically found with isub users) -- and essentially if you had airport, you were screwed.

When 10.2 came out though, that stopped happening for me. BUt yeah, the same thing happened -- airport activity caused static, unplug + plug in enough and you'll KP the machine.

Unfortunately there isn't much you can do, you might want to try a firewire controller though instead of a USB one.

[Sophus]

Originally posted by Link:
Wow I can't believe this bug still exists!

Way back in the OS 10.1 days, there was a bug with the USB audio driver (specifically found with isub users) -- and essentially if you had airport, you were screwed.

When 10.2 came out though, that stopped happening for me. BUt yeah, the same thing happened -- airport activity caused static, unplug + plug in enough and you'll KP the machine.

Unfortunately there isn't much you can do, you might want to try a firewire controller though instead of a USB one.

The bug is there all right!
If this was fixed in 10.2 at some point, would it be possible to extract the audio driver and use it with 10.3? Or is the different kernel versions preventing this? I know more about linux kernels than the mach kernel. A hint would be welcome. Thanks!