Currently Being ModeratedJul 6, 2013 8:09 AM (in response to Steve Burke)
USB draws power from the main power supply. There are limit to what that can provide.
My first suggestion is a "powered USB hub", that uses a wall plug to supplement USB power with AC from the wall. Available for as little as $20 from BestBuy or Target.
May fix all of your external-USB issues.
Currently Being ModeratedJul 6, 2013 10:04 AM (in response to Steve Burke)
I vote for Steve's solution---historically it is a winner.
However, if you can't get the powered hub for a while, offload the files from the external to the computer, then use Disk Utility on the iMac to erase and reformat the drive as Macintosh Extended (Journaled). Most of these external are shipped formatted for Windows but one that both Macs and peecees can use.
There are many reports across the forums that having a native Mac format on a portable external drive helps with the power drain issue. However, if you must share the drive with a Win computer, don't reformat.iMac 27-in; Mid 2010 2.93G i7 Quad, Mac OS X (10.6.8), 12GB RAM; ATI5750 1G VRAM
Currently Being ModeratedJul 6, 2013 2:06 PM (in response to Allan Jones)
Both the USB and external hard drives have always been able to be viewed onnthe desktop up until recently without extra power. The external hard drive is actually plugged into a power supply and is still not scene on the desk top.
How am I supposed to use disk utility if the computer is not recognising the external devise?
Currently Being ModeratedJul 6, 2013 2:50 PM (in response to Steve Burke)
Go with the powered hub ... common enough item at computer parts stores and Best Buy.
As to "why now"? Maybe the power supply has lost just a little of its original capacity and now cannot run them while still running the main system.
Currently Being ModeratedJul 7, 2013 12:26 AM (in response to steve359)
The portable hard drive is pluged into a seperate power supply. The light is on and it is working. For some reason it is still not being recognised and showing on the desktop or disk utility.
Currently Being ModeratedJul 7, 2013 12:57 PM (in response to WZZZ)
It's a portable LaCie drive. There is power, the light is on, and its definitely running. It's just not showing up.
Just booted up from the start up DVD and its not recognised there either.