iMac will not boot completely, screen goes white
While starting my Mac, the apple logo displays and the bar showing pro=gression moves about 1/3 of the way then the screen fades and goes to white. The mouse is visible but the suystem will not boot up. I have tried Disc repair in recovery mode and it says am=ll is OK for the Mac and for the OSX. I am able to get here in recovery mode. When I try to restart it does the same thing over and over. No error message is displatyed at any step.
iMac, OS X Yosemite (10.10.1)