Posted by Pierre Igot in: Macintosh
December 20th, 2003 • 6:21 am

There are days when I get really tired of all the glitches with USB devices in Mac OS X. Today, I came back to my machine to wake it up from sleep, only to find that my cursor had disappeared yet again, in spite of my precautions.

After using my computer in the dark with the keyboard for a while, I ended up hitting cmd-shift-Q to get out of the quagmire. It was then that I saw my mouse pointer reappear in the Finder, but it was stuck and not responding to mouse movements. I changed the USB port used for the mouse, to no avail. I started thinking that my mouse was dead. But then I tested the mouse on my PowerBook G4 and it was working fine. I restarted the whole computer, and it still wasn’t working. I ended up plugging it into yet another USB port, where it worked. Then I noticed several other USB devices were not longer working either. In fact, all the devices plugged through the USB ports provided by my secondary monitor, an Apple FP 17″ display connected to the video card using an Apple DVI-ADC Adapter, were no longer working. I turned everything off and back on, still to no avail.

This has happened once before. For several days I was unable to use all the ports on the secondary monitor. Then all of a sudden it started working again. I find this highly irritating. Is it a software isse? A hardware issue? Is there any way to diagnose or pinpoint the problem?


8 Responses to “USB, SCHMUSB”

  1. brian w says:

    Does a secondary monitor running through an adapter provide “clean” power to a USB device? Maybe you should try a powered USB hub if you’re using a lot of USB periphs, to see if you can get a more reliable power source.

  2. Pierre Igot says:

    I am not sure what “clean” power is, but the Apple DVI-to-ADC adapter comes with its own power supply, and presumably provides the USB ports on the ADC monitor with all the power that they need and that the DVI port itself cannot provide.

    In any case, the ports are completely unresponsive now, even after several restarts, a general PRAM reset, etc. As I said, this has happened once before, and resolved itself without warning several days later.

    Very puzzling — and frustrating!

    I do have a powered USB hub already (fortunately), which enables me to get most of my USB devices work even with only the 2 USB ports on the main monitor and the 2 USB ports on the G4 itself. But even that is not without its glitches. Occasionally, the USB hub simply stops working as well. Same type of unexplained behavior.

    What’s even weirder is that, since the USB ports on the secondary monitor have ceased working, the 2 USB ports on my Apple Pro keyboard (black model) have ceased to work as well. But I’ve connected a newer Apple keyboard (white one with solid plastic) and the two ports on that keyboard work just fine. Totally weird. I suspect that, when the USB ports on the secondary monitor start working again, the 2 ports on the older keyboard will start working again too.

    Too much USB voodoo for my taste.

  3. ganoe says:

    I have been seeing similar problems with my Powerbook running 10.3 Panther. I use a Belkin F5U224 (4 port USB hub) with a Belkin F8E813-USB mouse and Dazzle 6-in-1 card reader connected to it, but it seems like the issue is with the mouse. The light will go off for the mouse on the hub, and then usually it takes any other connected USB devices with it (though sometimes just the mouse goes). Other times I’ll be plugging my powerbook into the hub after being mobile, and the lights for the devices never come on and the Mac never sees them. When it’s doing this, plugging directly into the ports on the Powerbook doesn’t do anything either.

    I’l try plugging and unplugging the hub and all the different devices. Usually (but never on the first few tries) replugging-in the mouse will get everything else up and running, all the lights will light up on the hub, etc.

    My system is doing it right now, 2nd time today. Eventually, I know it’ll recover. I keep wondering if it is a bug in the hub.

  4. Pierre Igot says:

    I have made a little progress in my troubleshooting for this particular problem (USB ports on DVI-to-ADC flat panel dying). It looks like I can revive them by turning everything off, then restarting the computer by pushing the Power button on the DVI-to-ADC flat panel itself. (I used to push the one on the ADC flat panel instead, simply because it was easier to reach.

    But it sounds like you are getting away with plugging/unplugging and don’t require a restart. Consider yourself lucky :).

    I too still suspect my USB hub, but I have no information about which brand of hub might be more reliable than others. It seems to be pretty much a hit-or-miss market.

  5. Greg Hyatt says:

    My Apple mouse started doing this about a week ago with my one+ year old PowerBook G4 (800 MHz, running OS 10.3.3). Changing to the other port sometimes temporarily fixes the problem. I’m not using a hub. I have had the feeling it’s from overheating, which would be a hardware problem, but just this morning it’s continuing to work after I switched ports, and it’s well heated up. It’s a mysterious problem. I’ve tried zapping the PRAM with no apparent effect. My PB runs very hot at the back of the keyboard; is this normal? I have my preferences set so the trackpad only works when the mouse is not plugged in. When the mouse stops working, the trackpad works fine. Wouldn’t this be further evidence of a hardware problem rather than software?

  6. Pierre Igot says:

    I somehow doubt that it’s a heat-related or hardware problem. Yes, PowerBooks in particular can get fairly hot, but the heat is not usually located near the USB ports. Do you problems have anything to do with the computer going to sleep or waking from sleep?

    I haven’t experienced any problems with my USB ports lately, maybe thanks to some troubleshooting steps I took or possibly thanks to the Mac OS X 10.3.3 update. Of course, that doesn’t help you much. Did you try applying the Mac OS X 10.3.3 Combo update rather than the regular one?

  7. Henry says:

    I have just the mouse plugged into the back of my Powerbook G4 500mh and i have the same problem.. Every now and again the IR light on my mouse will go off and my mouse dies on me.

    Sometimes after i wait a while it will work again when i plug it back in but the problem always seems to happen when i bump the cable (where it attaches the the mouse).

    The mouse im using is the Microsoft Intelli Explorer.

    Sounds like USB driver touble to me as well.


  8. Greg Hyatt says:

    I discovered, finally, that it was my Apple, single button, ProMouse. One or more of the wires going in were broken from flexing/use and the problem was intermittent enough to make me think it was not really the mouse. Reading about various USB problems made me a little paranoid and temporarily blinded me to the real problem. I have repaired it using instructions at the website It works perfectly now and I have no USB problems and assume I never had any in the first place. Thanks to all who responded to my submission, and I recommend that website if you need to repair your Apple ProMouse. It’s not easy, takes about an hour, but it’s worth it if you don’t like to throw things away.

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