Usb Over Current Message?, Why am I getting this message? Options

[pushtobreak]

Anyone else ever get this message? It seems to be getting worse or maybe it's just bugging me more. I've only got a Logic7 dongle, a Motu fastlane midi interface and the qwerty/mouse plugged in. I thought it was the UC33 controller, but I'm still getting the message without it plugged in. I'm getting more ram soon could that be it?

I tried a USB hub to try recofiguring things. I was actually hoping to use another USB device. The hub didn't work at all. I did tons of research and found there have been some problems with hubs and macs. My problem was unpredictable behavior from the device(s) plugged into the hub. Now I just want to get to the bottom of the original problem, but if anyone has any advice about USB hubs I'd appreciate it.
The "USB overcurrent" message usually comes up after the computers been on for a bit, but usually not when I'm even using anything other than the qwerty/mouse. If I power down it usually solves the problem for a while.

Machine Name: Power Mac G5
Machine Model: PowerMac7,3
CPU Type: PowerPC G5 (3.0)
Number Of CPUs: 2
CPU Speed: 2 GHz
L2 Cache (per CPU): 512 KB
Memory: 512 MB
Bus Speed: 1 GHz

[lepetitmartien]

Maybe you're just under the limit current and after a while some component heats up and bingo…

I think it's time for adding some hub… Someone knows a good one ?

Also, you should really add some RAM, you'll discover a different G5. OS X version?

[cornutt]

Every device on a USB bus, when it initializes, tells the host how much current it expects to draw from the bus. Something on the bus is drawing more juice than it is supposed to. The first thing I'd do is check all my cables and connectors. Flex everything back and forth and see if maybe there is a cable somewhere that has an intermittent short.

Failing that, you want to get a line-powered (not bus-powered) hub. I have a Belkin 5-port hub that works pretty well. Plug each thing into a different port. If you have a device that is drawing excess current, that might help isolate it.

[pushtobreak]

Are you using that Belkin hub with midi?

Maybe my problems have something to do with the combination of makes & models, but after some research I couldn't find any differences in hub specs. The one I bought was a Techgear powerd hub. The problem was, if a midi device was plugged in, some notes would intermitantly stick and when I put the qwerty/mouse in it would intermitantly select random things.

As far things heating up, I'm sure this has happened a couple of times when I first powered up.

The cables are all in practically new condition and never really get moved, but I suppose there still could be a short.

Any experiences with a USB hub for midi devices using a similar system?

Anyone know if there is any difference between front & back usb ports? I assume the extra port on the back of the qwerty is less capable because it shares with the qwerty/mouse.

Every device on a USB bus, when it initializes, tells the host how much current it expects to draw from the bus.

Does this happen each time the computer is turned on?

Thanks for the advice guys.

[cornutt]

Are you using that Belkin hub with midi?

Yes, I'm currently using it with an Edirol UM-1. I've also used it with an MOTU Midi Express USB, but it had an odd quirk in that setup: every time I tried to power the Mac down, the USB would start it right back up. Other than that, it worked fine.

Maybe my problems have something to do with the combination of makes & models, but after some research I couldn't find any differences in hub specs. The one I bought was a Techgear powerd hub. The problem was, if a midi device was plugged in, some notes would intermitantly stick and when I put the qwerty/mouse in it would intermitantly select random things.

Hmm. The only thing I can think of is, when you plug in the MIDI interface, the whole hub for some reason goes into "isochronous" mode, in which error correction and retry is disabled. Still seems like it should not have behaved that badly.

Anyone know if there is any difference between front & back usb ports? I assume the extra port on the back of the qwerty is less capable because it shares with the qwerty/mouse.

I don't know about the difference between front and back ports on that system. My G4 doesn't have any front ports. It has two back ports, and the manual makes a point of saying that they are separate buses. If you have an Apple flat-screen display with USB ports on the back, that's another bus.

Those ports on the back of the QWERTY keyboard can't supply very much current, because they are just an extension of whatever bus they are on. They really aren't good for much other than plugging your mouse in. I've even seen some memory sticks that they could not power.

{concerning USB devices identifying how much current they draw}Does this happen each time the computer is turned on?

Yes. It also happens when a new device is plugged in, or whenever the bus is reinitialized (such as coming out of sleep).