I have a MacBook Pro running 10.4.11 from 2006 or 2007 with a problem during start-up. The computer will boot and then after showing the desktop, menu bar, and dock (but before icons appear on the desktop), the screen will fade to blue. After a few seconds the desktop will reappear and then fade to blue again. This cycle continues repeatedly. Does anyone have any ideas? Thanks.

3 Answers 3


Had a similar issue recently. Try zapping the PRAM, it worked for me. http://support.apple.com/kb/ht1379

  • Just tried it, didn't help. Other options?
    – hpy
    Commented May 10, 2011 at 2:09

That sounds like a very strange problem. First of all, if your system is ever running well enough to let you use it, try checking the Console (/Applications/Utilities/Console.app) for any error messages that might shed some light on the problem.

It's tough to diagnose without seeing the problem firsthand, but from my own personal experience, I might suspect overheating, as the first visible sign is often quirky display issues. Your MacBook Pro is definitely old enough to have accumulated a lot of dust and other gunk inside which can cause ventilation problems and lead to overheating very quickly.

Does this problem happen every single time you boot the machine, regardless of how long it has been turned off? Does the display respond to input at any time during the strange cycling? (Can you move the mouse cursor around, and does it stay where you put it?)

If you are lucky enough to have an Apple Store nearby, you could have it checked out at the Genius Bar (make an appointment first) -- though they won't fix it for free because it's definitely out of warranty by now.

  • Thank you for your quick response! OK, so the display DOES respond to mouse movement. In fact, the computer responds to commands, and the Finder is loaded briefly, before everything fades away as if the operating system completely reloads/resets. Any ideas?
    – hpy
    Commented May 10, 2011 at 2:08
  • 1
    @penyuan When everything fades away and comes back, is the system in the same state it was before it started to fade (e.g. mouse cursor in the same position), or is it in a new "reset" state?
    – Austin
    Commented May 10, 2011 at 2:35
  • (1) The mouse cursor is in the same position (2) during the few seconds before everything closes, I could click on a program in the dock and it would start loading (sometimes the window appears), but then everything (including Finder, Dock, menubar) would close again and the screen fades to a blue background (3) again during those few seconds, I tried to open system preferences, then the machine froze with a spinning grey wheel (the one you seen during boot) in the middle (the background including mouse is frozen).
    – hpy
    Commented May 10, 2011 at 3:28
  • 1
    @penyuan You said that it fades if you click an icon in the Dock. If you do nothing, does the fading problem still occur? How often does it occur? Does it happen at regular intervals (e.g. exactly every 10 seconds). Also, please edit your question to add any of this relevant info to it so others who might want to help can benefit from it. :]
    – Austin
    Commented May 10, 2011 at 4:28

Yes - as long as this happens each and every time, you will be able to figure out what process is crashing fairly easily. It will likely be logged in /private/var/log/system.log and the console log but the messages may be obscure or hard to discern from "the normal noise". You might try a few steps to isolate the issue further before attempting a fix.

  1. Boot into safe mode
  2. Make a new admin account (for debugging)
  3. Turn off auto-log in (so you have more control)

Now when you reboot your mac - you can log into the new account and see if the system itself is crashing or if the user account has problems. Assuming the new account is fine, then log out and log in to the old account with the blue screen issue. Sometimes just a safe boot clears out some bad startup items and fixes this issue - other times it's related to the changes you have made to the account over time and you will have to take further action to remedy the failure.

Once you've narrowed down the cause to being system-level or user-level you can then proceed on the steps to fix. The process to fix these differ, but in a nutshell: user issues get fixed by disabling whatever is crashing or moving just the user files that are not corrupt to a new user (by hand or via archive install and not preserving the user folders) Archive install and preserving will usually correct a system issue in the unlikely case that the new user has the same looping blue screen as the existing user.


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