G4 DDM = poor USB connections

Discussion in 'PowerPC Macs' started by Patth9, Feb 7, 2015.

  1. Patth9 macrumors regular


    Jun 28, 2007
    Trying to keep my Power G4 Duel processors MDD Mac running. Having trouble with my USB PCI cards. My plug-ins work sporadically,i.e., must move the keyboard and wireless mouse around to get the devices to work. I still use this Mac minus the internet. How would I know if the problem is the PCI cards (I have 2 USB2 cards) or where the USB cards are plugged into?
  2. bunnspecial macrumors 603


    May 3, 2014
    With these computers now over 10 years old, ruling out dirt and oxidation is always a good place to start.

    I'd suggest removing both cards and giving both the card contacts and slot a good cleaning. Denatured alcohol on a clean, lint free cloth is a good place to start for the card contacts. A pencil eraser is good if you need something a little more aggressive. The slots are harder to clean, but denatured alcohol on a lint free cloth followed by compressed air can do a decent enough job.

    That's the easiest thing to rule out, and if that doesn't help we can look for other problems.

    By the way, from the read of your post, it looks like you are plugging your keyboard and mouse into the expansion cards-I have a personal rule against plugging keyboards and mice into USB cards. Mine always get plugged into either the USB ports on the computer, or into the ports on an ADC display. These devices don't in any way benefit from the greater speed of USB 2.0(why I'm assuming you have USB cards), and there are plenty of downsides to using them in expansion cards. The biggest one I can think of is that they may not work until the appropriate extensions are loaded by the OS, which leaves you up a creek if you need to do anything with Open Firmware or some other startup command. I'd promptly move them to the built-in ports if this is indeed the case.

    (this post typed from a Quicksilver G4 that has a USB 2.0 card installed, but has the keyboard plugged into the ADC cinema display and the mouse plugged into the keyboard)
  3. poiihy macrumors 68020


    Aug 22, 2014
    Are the Apple Cinema Displays completely powered by the ADC port? So then the USB goes through the ADC port and through the graphics card?
  4. eyoungren, Feb 8, 2015
    Last edited: Feb 8, 2015

    eyoungren macrumors Core


    Aug 31, 2011
    ten-zero-eleven-zero-zero by zero-two
    Yes, ADC displays get their power through the ADC port.

    And nevermind, I am thinking about the A1006 DVI/ADC converter. Just the ADC display itself, yes the USB would go through the ADC port.
  5. Patth9 thread starter macrumors regular


    Jun 28, 2007
    Thanks, bunnspecial! This sounds like a good place to start. I'm going to use the denatured alcohol on a lint free cloth and canned air tomorrow. You mentioned the USB plugins that come on the G4. Is there a way to clean them too, as they aren't behaving very well either? Thanks so much for the tips, I am very appreciative. Patt

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4 February 7, 2015