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Thread: Bad USB port on 23" Cinema Display...

  1. #1
    Join Date
    Jun 2003
    Location
    UK
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    Default Bad USB port on 23" Cinema Display...

    Thank heaven for Apple Care!

    I bought a Mighty Mouse when they were first introduced, and I love it. But they kept breaking! Like, three times!

    At some point, about a year ago, an Apple Care tech suggested that perhaps the USB port on the 23" Cinema Display was delivering a damaging voltage to the Mighty Mouse.

    Recently, one of the 2 USB ports on the display failed. I have just RMA'ed the display and had it replaced with a new one, and a new Mighty Mouse.

    Other symptoms of display malfunction were intermittent flickering of the display throughout a small range of brightness near the upper range of brightness, and residual ghost images present when the flicker was evident.

    I'll say it again; thank heaven for Apple Care.
    "illegitimis non carborundum"

  2. #2
    Join Date
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    Concord, CA
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    AppleCare saved my bacon on the MDD. Cost of the replacement mobo plus labor would have been more than AppleCare. Have not needed to use it yet on my G5 nor iBook G4.

    About the display USB port, I thought that it was an unpowered hub and that it gets its power from the connection to the G5 USB port. Maybe not. k

  3. #3
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    Quote Originally Posted by kaye
    About the display USB port, I thought that it was an unpowered hub and that it gets its power from the connection to the G5 USB port. Maybe not. k
    Good question, Kaye, and that begs the same question about the Firewire hub in the display. Anybody know for sure?
    "illegitimis non carborundum"

  4. #4
    Join Date
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    I never use nor hook up the 23" Cinema HD Display FW400 and USB2 connectors to my G5. Everything I have is FW800 powered hubs, USB2 powered hub, USB1.1 powered hub, or direct connect to the back of the G5 for my one FW400 Granite device which has their heavy duty FW400 connector and is powered.

    In order to get info from System Profiler, I connected the Cinema connectors to FW400 and USB2 ports on the back of the G5. I don't have anything connected to the Cinema ports. System Profiler shows two FireWire Buses and a lot of Unknown Devices, none of them show the Cinema. No Cinema and no hub associated with it.

    USB on the other hand shows, among lots of other things:
    USB High-Speed Bus:

    Host Controller Location: Built In USB
    Host Controller Driver: AppleUSBEHCI
    PCI Device ID: 0x00e0
    PCI Revision ID: 0x0004
    PCI Vendor ID: 0x1033
    Bus Number: 0x4b

    Hub:

    Version: 0.01
    Bus Power (mA): 500
    Speed: Up to 480 Mb/sec
    Product ID: 0x911f
    Vendor ID: 0x05ac (Apple Computer, Inc.)

    Apple Cinema HD Display:

    Version: 1.35
    Bus Power (mA): 500
    Speed: Up to 1.5 Mb/sec
    Product ID: 0x921e
    Vendor ID: 0x05ac (Apple Computer, Inc.)

    Various Apple sources:

    Peripheral Devices on Your Desktop

    Every Apple display has a FireWire 400 hub and a USB 2.0 hub, each with two ports. Use the FireWire ports for connecting high-performance devices like digital cameras, and camcorders. And whether you’re using your display with a Mac or a PC, you can make best use of all the latest USB 2.0 devices, including iPods and industry-standard printers and scanners.


    Connectors: Two-port, self-powered USB 2.0 hub, two FireWire 400 ports and Kensington security port

    From Manuals, downloaded
    Apple (20-inch, 23-inch and 30-inch) Cinema Display User's Guide which is a pdf file.

    Interfaces
    The back of the display has:
    • Two USB ports
    • Two FireWire ports

    Power Adapters
    • 65 Watt (W), model A1096 (20-inch display)
    • Input: 100-240 volts (V) alternating current (AC), 50-60 hertz (Hz)
    • Output: 24.5 V - 2.65 amperes (A) maximum
    • 90 W, model A1097 (23-inch display)
    • Input: 100-240 V AC, 50-60 Hz
    • Output: 24.5 V - 3.70 A maximum
    • 150 W, model A1098 (30-inch display)
    • Input: 100-240 V AC, 50-60 Hz
    • Output: 24.5 V - 6.10 A maximum

    If I had to sum this all up, my guesstimation would be that the the Cinema ports are like this:
    1. USB2 powered hub but really only enough power for low power draw devices that get their power from the hub. A printer or scanner normally are powered devices so they don't draw from the hub.
    2. FW400 not a powered hub and gets its power from the G5. Apple's examples above about what you can connect to these ports are essentially low power devices or self powered. Powered devices of course don't draw power from the Cinema port.
    k

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