# "A USB Device is Drawing Too Much Power..."



## fabjance (Sep 2, 2010)

I recently bought a small external hard drive that draws power from the computer itself (no external power supply). I was transferring files from a drive WITH an external power source to the new drive, and that error came up and the drive without a power source was ejected. So I removed the remaining drive and tried again with JUST the small external HD plugged in, and the same error message happened. So I tried again with the small HD with both USB plugs, and the same message.

Two things:
1. Now, when I plug it in it won't even register and the error message will immediately come up. But when I unplug the ethernet cord and try, it will register, but I haven't left it in for long enough to see if it stays. Is it possible that without the ethernet cord plugged in my MacBook will be able to maintain enough power to the drive to continue transferring files?

2. Last night I bought a USB hub with an external power source, thinking that this would solve my problem...thoughts?

Sorry if this is really confusing, I can answer questions anyone has if they're confused as to what I'm saying.


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## sinclair_tm (Mar 11, 2005)

Is the Macbook plugged in to the wall and still charging while you do this? If you Macbook is trying to do anything else, including being plugged into a network, you will most likely get this error from a cheap external drive. THe powered USB hub should fix this. The Macbook is designed to help maintain battery life, and therefore doesn't have the robustness of a desktop. Due to this, it's USB ports can not handle heavy power requirements, as both ports share the same power, where on a desktop or powered hub, the ports have more power available to them. Also, some external drive makers do not intelligently design their drives to operate efficiently, and thus will try to draw more power to make up for it. I have not had this error on my Macbook, because I use a powered hub just for this reason, that and I have more then 2 things to plug in all the time at home. I did get this error once on a desktop, and it was a cheap drive that then failed all together, and thankfully the desktop rejected it before the drive was able to take out the USB port.


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## fabjance (Sep 2, 2010)

thanks for the response.

yes, it was plugged in charging AND plugged into a network, I couldn't help the ethernet cord, my dorms do not have wireless because of the thickness of the walls =\


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