iMac gets stuck on the "White Screen of Death" during startup I have a 27" iMac (from 2011) that's running Yosemite and each time I turn the power on, it shows me the Apple logo, it starts to load, and the screen goes white and simply hangs there.

To solve this problem, I've done all of the standard procedures: resetting the PRAM, trying to reinstall the OS from a USB stick, attempting to use the Internet recovery feature, etc. But no matter what, it ends up on the same white screen.

When attempting to launch into safe mode, this is the last thing I see before the computer cuts to the white screen:



Any help in getting the computer booting again would be appreciated.
If you're lucky, this is a common, and easily remedied iMac problem.  Just tell me this: does your system come up in a usable state if you hold down the shift button while powering up?  (That combination gets you into "safe mode".)