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"because a usb device is drawing too much power"

I realize that this issue has come up several times over the years but I can't seem to find the definitive answer ... if there IS one!

Using a PowerMac desktop computer and getting the error message sporadically. Doesn't seem to have much to do with what is or isn't plugged in USB-wise. It's just become a huge nuisance to have the error message window (sometimes 5 or 6 in rapid succession) pop up and take over my screen.

Can anyone help?

Mac OS X (10.7.5), 16 GB 1333 MHz DDR3

Posted on Apr 23, 2016 4:57 PM

Best reply

Eric Root

Level 10

684,117 points

Posted on Apr 24, 2016 8:01 AM

You could try getting a powered USB hub so the computer wouldn't be the power supply.

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27 replies

May 28, 2016 8:16 AM in response to Ralph-Johns-UK

@Ralph: Thank you for your very thorough examination of my problem. Below is another screen shot showing information on other peripherals.

NOTE: I have a Magic Mouse that is connected through Bluetooth. I have a printer that is connected wirelessly.

I have THREE external hard drives - one is using the USB in front of the tower and two are using rear USB ports. Of these, only ONE is on all the time (my TimeMachine backup drive).

I typically plug my iPhone recharging cord into the back of the monitor.

And I plug my iPad recharging chord into the keyboard.

However, as a test, I tried to unplug BOTH recharging cords and am still getting the message.

Anything else look suspicious?

May 28, 2016 8:19 AM in response to Eric Root

I have not but that is definitely an option if this IS truly a power issue.

What makes me question it, is because the issue is WAY too sporadic and often goes for weeks without popping up its ugly head, all the while nothing else has changed.

BDAqua

Level 10

239,993 points

May 28, 2016 10:27 AM in response to KatieOConnell

Does it ever do it without the iPad plugged in?

May 28, 2016 11:48 AM in response to BDAqua

BDAqua - Yes, it does.

May 28, 2016 1:18 PM in response to Eric Root

Hi Eric,

The issue there is that some of the Internal Controllers send power to the USB ports AND to internal devices.

In the case of some early MacBook Pros the cable for the internal iSight as the first ones were called ran up the back of the screen and through the hinge.

Well used (as in terms of opening and closing the lid) caused problems for some users with either the cable being slightly pulled out of the camera connection with all sorts of intermittent issues or being shorted out in the hinge through wear.

Whilst that does not apply in this set specifically.

The last set in the Device Tree,where the link to the External display also plays a role, would be the place to start.

Reseating all the connecting cables might just be the thing.

9:18 pm Saturday; May 28, 2016

 iMac 2.5Ghz i5 2011 (El Capitan)
 G4/1GhzDual MDD (Leopard 10.5.8)
 MacBookPro 2Gb (Snow Leopard 10.6.8)
 Mac OS X (10.6.8),
 iPhone and an iPad (2)

May 28, 2016 1:38 PM in response to Ralph-Johns-UK

@Ralph: I'm not sure if you're last sentence is instructing me to unplug / replug in all USB devices or if that's a reference to something else.

Are you suggesting that the USB Port screen shot I posted shows NO overuse of devices?

I'm not sure what I'm hearing from you. Would you kindly clarify?

Thanks so much for your time.

May 28, 2016 1:44 PM in response to KatieOConnell

Umm,

I have a G4 tower of some vintage (2003)

My Keyboard is only USB 1.1 throughout where as yours is a Hub at USB 2.0 and then the keys part at USB1.1

I am surprised that it says it can supply enough power to the iPad to charge it as well as supply the keyboard.

In fact it is one place where the figures don't appear to add up.

If it can supply 500mA and 300mA are being used it seems odd that the iPad is reporting it can see 500mA use 500mA but still leave some "spare" like the keyboard is showing with it's 200mA

And then below that you have the Keys part drawing power as well.

The Keyboard Hub is essentially the ports (mine has one at each end) on the keyboard as a lump of plastic, whereas the Keyboard (as Function) itself is regarded as a separate device linked to that hub.

Therefore that "Hub" powers devices connected to it and the keyboard (keys) itself.

In Applications/Utilities is the Console App

It might pay to look at this at the time the issue happens and see if it can shed any more light as to which device or part of the tree has the issue.

It might also involve one of the drives drawing more power if the Drive is "sticking" but I presume that they have their own Power Cords ?

I do have a Western Digital My Passport for Mac that draws power via the USB cable on my iMac.

9:44 pm Saturday; May 28, 2016

 iMac 2.5Ghz i5 2011 (El Capitan)
 G4/1GhzDual MDD (Leopard 10.5.8)
 MacBookPro 2Gb (Snow Leopard 10.6.8)
 Mac OS X (10.6.8),
 iPhone and an iPad (2)

May 28, 2016 4:06 PM in response to KatieOConnell

HI,

As the Cable from the Mac to the Display also carries the USB data I would also disconnect and re-connect that as well.

On my older G4 it is one cable.

It supplies the power to the Screen and the USB ports on the Display as well as the Control for ON and Off that the Display has.

Mine is the big old Apple version of the DVI connector (I think they called it Apple Studio Display connector.

The Graphics card also includes a DVI connector port as well.

I have posted separately on the Device Tree pic and the values apparently used.

9:50 pm Saturday; May 28, 2016

 iMac 2.5Ghz i5 2011 (El Capitan)
 G4/1GhzDual MDD (Leopard 10.5.8)
 MacBookPro 2Gb (Snow Leopard 10.6.8)
 Mac OS X (10.6.8),
 iPhone and an iPad (2)

May 28, 2016 3:26 PM in response to Ralph-Johns-UK

Ralph - This is helpful. I will stop using the keyboard to recharge the iPad and see if that might be a workaround.

Again, thanks for all of your time and expertise - much appreciated!

May 29, 2016 8:39 AM in response to Eric Root

Okay - I'm convinced. Now looking at USB hubs but this brings up a new issue: Can I use one that provides USB 3.0 service when I have devices that are USB 2.0 (or lower)?

Check out this device, for instance:

BDAqua

Level 10

239,993 points

May 29, 2016 9:54 AM in response to KatieOConnell

They're supposed to be backwards compatible, but I have seen reports of some problems...

http://electronics.stackexchange.com/questions/161570/can-a-faulty-usb-device-fr y-other-devices-on-the-same-hub

Maybe it only really applies to USB3-C devices...

http://money.cnn.com/2016/02/05/technology/usb-c-cords/

If woried...

https://eshop.macsales.com/item/Macally/TRIHUB4/

https://eshop.macsales.com/item/Macally/TRIHUB7/

May 29, 2016 1:43 PM in response to KatieOConnell

Hi,

My tuppence worth (British old school money before 1974 tuppence was two old pennys the phrase is even older).

I don't have a USB 3 hub but do have a USB 3.0 drive using it's USB 3 cable to connect to my iMac that only has USB 2.0 ports.

As the USB 3.0 cable has a ridge in it at the device end I could not use and older cable.

9:43 pm Sunday; May 29, 2016

 iMac 2.5Ghz i5 2011 (El Capitan)
 G4/1GhzDual MDD (Leopard 10.5.8)
 MacBookPro 2Gb (Snow Leopard 10.6.8)
 Mac OS X (10.6.8),
 iPhone and an iPad (2)

"because a usb device is drawing too much power"