self-powered usb hub
in [Mac Systems]
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From: E Z Peaces on 5 May 2008 18:54 I have a G4 Mini, a Ministack Firewire disk with three usb jacks, and a hub with seven usb jacks. The Ministack is my normal startup disk. The hub came with a wall wart power supply. Without the power supply, things work. I'd rather use the power supply to be sure to have enough current for my usb devices. With the wall wart powering the hub and the hub connected to the external disk, the Mini won't recognize the external disk on a cold start. It will recognize it on a restart. Ministack tech support suggested plugging the hub into my Mini instead of my Ministack. I haven't dared do it. I've discovered that some self-powered hubs isolate their power from what's upstream. Mine doesn't. That's probably why it keeps my external disk from being recognized on a cold start. I wonder if it's dangerous. If the hub's wall wart provides voltage slightly higher than the usb voltage regulator in my Mini, could the regulator in my Mini sink current from the hub, overheat, and be damaged?
From: weedhopper on 5 May 2008 21:58 "E Z Peaces" <cash(a)invalid.invalid> wrote in message news:fvo36v$na0$1(a)registered.motzarella.org... >I have a G4 Mini, a Ministack Firewire disk with three usb jacks, and a hub >with seven usb jacks. The Ministack is my normal startup disk. > > The hub came with a wall wart power supply. Without the power supply, > things work. I'd rather use the power supply to be sure to have enough > current for my usb devices. > > With the wall wart powering the hub and the hub connected to the external > disk, the Mini won't recognize the external disk on a cold start. It will > recognize it on a restart. > > Ministack tech support suggested plugging the hub into my Mini instead of > my Ministack. I haven't dared do it. > > I've discovered that some self-powered hubs isolate their power from > what's upstream. Mine doesn't. That's probably why it keeps my external > disk from being recognized on a cold start. I wonder if it's dangerous. > If the hub's wall wart provides voltage slightly higher than the usb > voltage regulator in my Mini, could the regulator in my Mini sink current > from the hub, overheat, and be damaged? What does "wall wart" stand for? While I'm waiting for your answer, I will work on your problem.
From: Clark Martin on 5 May 2008 22:56 In article <7WOTj.5944$_.849(a)bignews8.bellsouth.net>, "weedhopper" <wendelhopper(a)comcast.net> wrote: > > What does "wall wart" stand for? > It doesn't actually stand for anything. A wall wart is a power supply where the actual power supply is in a small case that plugs directly into the wall. The name is a reference to it being a wart on the wall. -- Clark Martin Redwood City, CA, USA Macintosh / Internet Consulting "I'm a designated driver on the Information Super Highway"
From: Jolly Roger on 5 May 2008 23:54 In article <7WOTj.5944$_.849(a)bignews8.bellsouth.net>, "weedhopper" <wendelhopper(a)comcast.net> wrote: > > "E Z Peaces" <cash(a)invalid.invalid> wrote in message > news:fvo36v$na0$1(a)registered.motzarella.org... > >I have a G4 Mini, a Ministack Firewire disk with three usb jacks, and a hub > >with seven usb jacks. The Ministack is my normal startup disk. > > > > The hub came with a wall wart power supply. Without the power supply, > > things work. I'd rather use the power supply to be sure to have enough > > current for my usb devices. > > > > With the wall wart powering the hub and the hub connected to the external > > disk, the Mini won't recognize the external disk on a cold start. It will > > recognize it on a restart. > > > > Ministack tech support suggested plugging the hub into my Mini instead of > > my Ministack. I haven't dared do it. > > > > I've discovered that some self-powered hubs isolate their power from > > what's upstream. Mine doesn't. That's probably why it keeps my external > > disk from being recognized on a cold start. I wonder if it's dangerous. > > If the hub's wall wart provides voltage slightly higher than the usb > > voltage regulator in my Mini, could the regulator in my Mini sink current > > from the hub, overheat, and be damaged? > > What does "wall wart" stand for? > > While I'm waiting for your answer, I will work on your problem. You're not fooling anyone, Zero. -- Please send all responses to the relevant news group. E-mail sent to this address may be devoured by my very hungry SPAM filter. I do not read posts from Google Groups. Use a real news reader if you want me to see your posts. JR
From: Tim Murray on 6 May 2008 00:23
On Mon, 5 May 2008 18:54:21 -0400, E Z Peaces wrote: > I have a G4 Mini, a Ministack Firewire disk with three usb jacks, and a > hub with seven usb jacks. The Ministack is my normal startup disk. > > The hub came with a wall wart power supply. Without the power supply, > things work. I'd rather use the power supply to be sure to have enough > current for my usb devices. > > With the wall wart powering the hub and the hub connected to the external > disk, the Mini won't recognize the external disk on a cold start. So what happens? Does it boot from the internal drive? What's between the mini and the Ministack? USB or Firewire? You are not doing yourself any favors booting from an external drive, by the way. Why do you do this? > It will recognize it on a restart. Because it's at a "ready" state. > Ministack tech support suggested plugging the hub into my Mini instead of > my Ministack. I haven't dared do it. > > I've discovered that some self-powered hubs isolate their power from > what's upstream. Mine doesn't. That's probably why it keeps my external > disk from being recognized on a cold start. I wonder if it's dangerous. > If the hub's wall wart provides voltage slightly higher than the usb > voltage regulator in my Mini, could the regulator in my Mini sink current > from the hub, overheat, and be damaged? Sounds to me like the external simply is not coming ready in time to be seen by the Mac. Unless your hub is of shoddy construction, you're not going to add voltage to the USB. |