Why is my Mac showing a white screen?

Answer 1

A common question. While people have heard of the blue screen of death for decades, in the usual defiant manner of Apple the screen is white.

One step at a time.

1. Force shut down your Mac by holding the power button down until the Mac turns off. Disconnect every device connected to your Mac(printers, USB drives, ect.), leaving the keyboard, mouse and monitor attached.
2. Try re-starting your Mac while everything is disconnected. If your computer re-starts without having any issues, that means that the problem is one or more of the devices you removed. If it did restart plug one device in and restart until you find the problem. If it didn't work continue.
3. Safe mode. A way of starting your computer with a minimum of things running. To start in safe mode push the power button. As soon as you here the chime hold the shift key until the apple logo appears, then release. Be patient.
4. If it starts in safe mode that may be enough to jog your computer back to life and give a shot at a normal boot.
5. If we are still having problems Do the same method as booting in safe mode, but instead of shift hold Option and R. This will bring up OSX utilities.
6. Choose disk utility and repair disk. When it is done try a reboot. If it won't step back to step 2. If after that you it doesn't work continue
7. NVRAM. Same process as safe mode this time Command and Option and P and R. Just hold it this time and it will eventually restart itself
8. If none of this worked, in the display from step 3 there is an option for disk utility factory reset. There is something to keep in mind know.
9. I hope you have been making backups of you're system. If not and you were able to sign on in safe mode, get as much personal data as you can.
10. If none of this worked, in the display from step 3 there is an option for reinstall OSX. There is something to keep in mind now before this final step. You will need to have a new copy of OSX.

Good Luck!