I have raspberry pi model B that I can only connect to a USB hub if I get the plug in the port just right. It's actually the second one in a row where I've had this problem. The full details are here:
http://dllahr.blogspot.com/2015/03/raspberry-pi-2-and-case-of-unreliable.html
I'm running raspbian. The USB hub is independently powered and connected to two western digital 2 TB drives. When I connect the USB hub "normally" (plug it all the way in like you normally would) to the pi and then check dmesg, I get a brief message about having problems with the hub and no information about the drives themselves.
When I completely disconnect the hub, dmesg indicates that it found the hard drives, but then immediately indicates they were disconnected.
And goldilocks then discovered that by plugging in the hub, and then slightly pulling it back the USB connection is made and stays (it was just right). I tried the other USB ports on the pi and saw the exact same behavior. I tried the USB hub & drives with my raspberry pi 1, no problem. I then returned my raspberry pi 2 to the store where I bought it (Microcenter, Cambridge, MA, US) and got a new replacement - and saw the exact same problem. I tried different USB ports on this new pi, same exact problem / behavior.
I don't think it is a problem with the cable because it connects to my other raspberry pi without any problem, and also to my laptop without any problem. I don't think it is a power issue for the same reason - the hub is independently powered and plugged in, and it doesn't cause any problem with other raspberry pi.
Any thoughts? It seems like the odds of having a poor physical connection in 2 separate pi's should be very low unless there is a systematic manufacturing defect, or the problem is somehow not physical.
