04-18-2012, 12:30 PM

Hey all,
Is just me, or do you all get tired of the iMac/OS Lion not recognizing the USB when a new device is plugged into the computer and/or USB hub. There must be some flaw in the Apple OS that does not properly recognize a USB device or at least maintain a constant check of the USB ports. There are threads upon threads where this problem arises for various users time and again, with various complex solutions being offered.

What is the basic problem? Why must we, the purchasers and users of really high priced hardware/software, go through the various reboots, resets, etc, to get our USB equipment to work properly?

I switched to Apple to avoid this kind of malfunction in the PC/Microsoft world, but you know what? I rarely encountered USB problems in that world. Why?

04-18-2012, 02:15 PM

I've not run into that problem with either of my Macs or for that matter with the PCs that I own. What USB devices are you plugging in that are not recognized?

If you're using a hub, that could be part of the problem. USB hubs can be temperamental and intermittent which is one reason why I never use them. A powered USB hub is better than one not powered.

Also, using the USB ports on your Apple wired keyboard for hard drives and certain power consuming devices is not recommended. The USB ports on the Apple wired keyboard are good for mice and printers but that's about all.

04-18-2012, 06:03 PM

And by a powered hub, chscag means a mains powered hub. Computer powered hubs often drag too much power from the ports and cause problems.

04-19-2012, 06:05 AM

I love how it must be Apple's fault when a user has a problem caused by third party peripherals that nobody else seems to be having ...

04-19-2012, 09:42 PM

Some of you guys need to re-read the text. This is a recurrent problem.

I have tried two powered hubs, one by Belkin, one by Targus. I don't use the wired keyboard USB plugs for lack of power.

The devices that will not 'fire up' when plugged into the USB hubs are two iPhones (4 and 4S) and my iPad2. One would think these devices would be recognized, right?

When I do get the hubs working, there is no assurance the iMac 27 will recognize the next time. FWIW, it is quite cumbersome to plug/unplug USB on the back of the iMac 27. Largely done blindly due to awkward placement of the USB plugs, I can't easily plug/unplug USB devices without a hub.

Many others have reported this problem, not just me. But some avid Apple defenders just blow it off.

Go figure!

04-19-2012, 10:16 PM

The devices that will not 'fire up' when plugged into the USB hubs are two iPhones (4 and 4S) and my iPad2. One would think these devices would be recognized, right?

Both of those devices draw too much power for most hubs, even the so called powered ones. Use the USB ports on the back of your iMac. It's not that difficult to stretch around the back and plug in the cable. Either that, or leave a cable plugged in all the time and just attach the iPhone or iPad when you need to sync. You can't charge either device on your iMac anyway (in case that's what you were planning on doing).

04-20-2012, 05:16 PM

Thanks for the info. But it is not the power (it also happens with my camera and even thumb drives). The Targus USB port has two high powered ports so it has plenty of power, but the iMac still threw it offline. It has something to do with turning off the iMac, and I can restore the USB function by going through all the complex steps of resetting the machine and all permissions using Onyx. I still think it is a problem with the OS that concerns not polling the ports often enough. I'll keep digging for a solution.


BTW Nice B26!

04-20-2012, 11:20 PM

BTW Nice B26!

Thanks. Most folks can't tell which aircraft it is. The one in the picture is a Douglas B-26D which was used during the Viet Nam war to do low level bombing.

As to your USB problem: There may be something to what you say if even your camera and thumb drives are not being picked up. Why don't you run the Apple Hardware Test on the iMac to see what it might come up with.

04-22-2012, 09:49 AM

Once again, problem was solved and USB restored by 1) doing hard reset 2) using Onyx to 'fix' all permissions and clear all caches. I found the Apple Hardware Test on my Lion disc, but it requires disconnection of all USB hookups and so I doubt it will test the USB ports.

So the mystery remains: what keeps knocking the USB off-line on my iMac. I have yet to receive any thoughts as to 'why' this happens as opposed to how to fix it.

Plus the interesting personal attacks that I would dare criticize Apple at all! LOL!

04-22-2012, 09:57 AM

Maybe there is a hardware fault with your iMac. Did you ever take it into Apple and show them what is happening?

I have 2 iMacs here, Power PC G5 and Intel and I have 2 7-Port Belkin USB hubs (Powered). Never have I had an issue. iPhone, iPad, iPods, 10 Flash Drives, 10 External hard drives, 3 Cameras. Never once had an issue.

I have run the AHT here and never had to disconnect any ports from the machine.

04-22-2012, 06:38 PM

Thanks for the suggestion. You may be correct, as that would logically explain the problem. I can return to the Apple store eventually, but it is 315 miles north of me in Huntsville, AL. Still, I return there from time to time, and I do have Apple Plan.

04-23-2012, 06:36 AM

Let us know what they say, but everything you've said so far supports my previous post ...

06-11-2012, 11:52 AM

Try to uninstall all the drivers related to your dongle and then reinstall the correct one. With so many drivers installed on your system, you cannot reasonably keep track of which driver has been updated. To read more about this try looking here : Dealing with a missing hardware driver | Techyv.com