Upgraded from Mavericks, Boots Fine, but No USB

[subdivisions]

The upgrade from Mavericks went smooth, (HP Z600 Workstation, 36 Gig Ram), I boot Yosemite with no issue, but when i get to the login screen my USB is dead. If i boot -x safe mode, the usb is just fine.. Ideas? I know i had the same thing in mavericks and i had to delete some apples kext.. but i can't find it in yosemite

 

[Runi]

I do not know if we are having the same issue but in my case the USB is just hanging for about 5 minutes after boot. When my login screen pops up I can neither type or move the cursor. I have a screen calibrator connected to my main monitor and I can se that it is blinking during this hang and when the light becomes solid I know I can start typing.

 

[byasm32]

I do not know if we are having the same issue but in my case the USB is just hanging for about 5 minutes after boot. When my login screen pops up I can neither type or move the cursor. I have a screen calibrator connected to my main monitor and I can se that it is blinking during this hang and when the light becomes solid I know I can start typing.

me too.
my usb hanging for about 1.5min after boot....
don't know how to fix it.

 

[wender_reis]

I've made a clean install in my Z87-UD3H and got this issue after installing USB 3.0 kext (GenericUSBXHCI.kext) with Multibeast. Try to remove that and it started to work again. But I'm still having issues like freeze when the system starts.

 

[ERSCreeper]

USB 3.0 Kext is only for 5 & 6 series motherboards.