Grey screen with grey icon - not booting - how I fix?
I have four iMacs they are all unable too startup OSX and show the following symptoms, I was hoping someone could provide some insight into what the problem might me.
IMac #1: Power buttom flashes when switched on, but the screen remains blank
IMac #2: Grey screen shows a Grey FOLDER icon flashing
IMac #3: Grey statup screen show the apple logo and the loading spinner, but it never gets to the login screen
IMac #4: Grey startup screen shows the Apple logo briefly, then it changes to a 'no access' symbol (a crossed circle)
Im hoping that the problem are easy enough to fix and that I can do it myself, does anyone have a system that can help me narrow down what the issue may be?