3754 Views 4 Replies Latest reply: Dec 3, 2010 10:09 PM by Pondini
Usually when I see that it is a power problem on the USB bus. If I have my iphone, backup disk, and scanner all plugged in they're fine. If I then plug in my ipad, the entire thing will hiccup. All devices disappear and then reappear.
You can check this by running Console.app and selecting "All Messages" in the sidebar of logs. You should see a bunch of errors fly by about the USB having problems and various apps reacting to the reset.
The external drive is using a separate power supply. I have my keyboard and external hard drive plugged in to the USB's and then a USB hub. The Hub works fine as does the keyboard. Never a blip. The problem doesn't seem to be particular about when it happens. This is making me crazy. I have to click okay when the warning pops up before I can do anything else.
Thanks for both responses I've received. Any further suggestions?
See #A1 in [Time Machine - Troubleshooting|http://web.me.com/pondini/Time_Machine/Troubleshooting.html] (or use the link in *User Tips* at the top of this forum), for a handy widget that will display the backup messages from your logs.
See what that shows; there may be a problem with the backup, which results in TM ejecting the drive. If so, the disconnect may be a symptom, not a cause. If so, see #C2 there. If not, or if you're not sure, copy and post them here.
Also, to rule out other USB problems, disconnect everything but keyboard and mouse; connect the drive directly to your Mac (no hub).
Make sure all connections are snug and secure.
Try other ports, cables, and combinations of the two (a plug that works fine in one port may not make good contact in another one, and throw intermittent errors).