Showing posts with label hub. Show all posts
Showing posts with label hub. Show all posts

Sunday, May 26, 2013

Backfeed / problem USB Hub(s) on the RPi!

New Plugable high speed 7 port USB Hub

The first USB 7 port hub had major problems right from the start.  Even though it had a 2 amp power supply and was a package deal item on Amazon along with the Raspberry Pi.  It was a no name hub that would cause the keyboard to miss or repeat keys really bad.   So much so,  that I bought several keyboards while trying to find the problem.  Finally it burned out the USB connection to the Raspberry...  Not on the RPi itself .  The one on the hub.
 So the next one, I went with a name brand and made sure it was on the list of verified working devices for the RPi.  It was the Belkin F4U040 4 port hub.  I used it for a couple weeks before I  started having keyboard problems again.  I found that I could fix it by powering up the RPi first and then powering up the hub.  I also found that it was backfeeding the Raspberry Pi.   If I unplugged the RPi with the hub still plugged in,  the Raspberry Pi stayed turned on!   Not a good situation and could have really damaged the little computer!   I notice now they have it listed under the approved USB hubs, but with a note that it backfeeds.  Then it is listed TWICE under 'problem'  devices!  But it is still 'verified'!
 Well, I have been running my 3rd USB hub for a few days now...  No sign of a power