5 Replies Latest reply: Jan 26, 2009 7:11 PM by golferguy357
Robert Su1 Level 2 (345 points)
Hello everyone,

My daughter's MacBook Intel Core Duo had been connected to a BookEndz for two years. Through the connection, she had been using an external LCD monitor. She upgraded the unit to Mac 10.5.6 one month ago. Recently, the unit displays a warning box each time when it boots up. The warning says USB Over Current Notice. A USB device is currently drawing too much power. The hub is is attach to will be deactivated. This warning notice appears even without a connection any USB device or the Bookendz. She used the Hardware Test program and found everything was normal. We tried reset the system power management(?) to no avail. She tried reinstall Mac OS 10.5.6 and Mac OS 10.4.6 to no avail. Also, the two USB ports are not working at all. I assume that they are deactivated as the warning notice says. What is wrong with the MacBook? What should we do to correct it?

I appreciate your advice very much. Wishing you a happy new year.


Message was edited by: Robert Su1

G4 Sawtooth 1.3GHz, G4 iBook, G3 Desktop/G4 450MHz, G3 Imac, Mac OS X (10.4.11), i-rocks external storage
  • Soft Reset Level 4 (1,790 points)
    Hi Robert!

    A USB message like this will typically indicate either a bad USB cable, a bad device that's plugged into the USB port or the port itself is bad.

    On the left side of the MacBook (I refer to it as the I/O board) you also have a FireWire 400 port and Ethernet port. Are those working correctly? Secondly, if you plug in a USB-based device (such as an iPod or other product) and launch System Profiler (go to USB) does it show up as a connected device?

    It would seem to me that the potential point of failure (if you're getting the message with nothing plugged in and after resetting the SMC & PRAM) is the logic board. But again, I'm merely speculating via process of elimination.

    Are you near an Apple Retail Store or Authorized Service Provider? They have more extensive diagnostic tools and can also serve as a point of repair should the machine require it.
  • Robert Su1 Level 2 (345 points)
    No, the message comes up each time when the computer is booted, without anything plugged into any port. The firewire port is working. I have also suspected the failure of the USB ports or even the UBS unit on the logic board. Certainly, I also suspect the power management failure too.

    As you suggested, I plan to visit the Apple store for advice. Unfortunately, my daughter has this one for two years and does not have an extended warranty on it. If something wrong with the USB unit and if the USB unit cannot be replaced separately, the cost to replace the logic board is not cheap at all.

    This is the first time that I know that an Apple computer fails so soon. I have used Apple computers since its first or second line of production. The earlier models were still operational when I mothballed them. I wonder the quality of the Apple products is at issue that might be because Apple uses more foreign parts.


  • maclover009 Level 1 (65 points)
    Hey Robert,

    Your daughters computer has fried USB ports. These are not expencive to replace and should fix the problem. If the rest of the computer is functioning normally, it should be a simple fix. Did you try a PRAM reset?

    Instructions for PRAM can be found here:


    Also, make sure you did the SMC correctly. Even though the SMC has almost nothing to do with the USB ports it still may help.

    Instructions for SMC are here:


    Hope this helps!

    ~ Harris
  • Robert Su1 Level 2 (345 points)

    I have tried both PRAM and SMC a couple of times before. I will try them again. I did suspect that the USB units or ports or whatever was probably burned. I am glad to hear the cost for repairing or replacing the ports is not expensive. But, how is it usually?


  • golferguy357 Level 1 (0 points)
    I have been struggling with this USB over current notice for a long time now. Every time I would log on the box would come up even when i didn't have anything plugged in to the USB ports. The notice would also keep popping up after i clicked out of it. It came up almost once every minute which was very annoying while working. I found this article and reset the PRAM and the computer has been perfect ever since. I also used to have this problem where when i clicked on the bluetooth icon in the system preferences my computer would freeze up and i could never connect any bluetooth products. But, since this PRAM reset, the bluetooth has been working perfectly. This PRAM reset was a great help! Thanks