4 Replies Latest reply: Feb 9, 2012 2:17 AM by 50hz
50hz Level 1 (0 points)

Maybe somebody can help me out here.


My 24" imac dual 3ghz running 10.5.8 will only get as far as a blue screen loop with short flashes every 8-10 seconds. Safe mode is the only way to boot up and the flashes continue in that as well. There is also a short orange flash while the screen is still grey.


Attempting to boot from the system dvd results in a grey screen that tells me I need to restart. Booting from another system hard drive results in freezing - the wheel under the Apple logo stops spinning.


I have tried resetting PRAM and SMC. Repaired Permissions using Disk Utilities and Disk Warrior. Checked the hard drive, no problems. Did the hardware check (boot pressing d), which claims everything is fine.


Does anyone have an idea what's wrong with my machine?

iMac, Mac OS X (10.5.8)
  • rkaufmann87 Level 9 (55,238 points)

    Your system may be trying to tell you the HD is in trouble. Please look over Gray progress bar appears under Apple logo during startup


    You can also try rebooting again, when you hear the startup tone hold down the Option key and choose your internal HD. If it boots OK then navigate to System Preferences - Startup Disk and make sure the internal HD is selected and then restart again.


    If it still restarts in Safe Mode then run Apple Hardware Test per the instructions in your owners manual. If you no longer have the owners manual then click Support in the upper right of this page then click Manuals and navigate until you locate your manual. Run AHT in Extended Mode, if no errors come up after the first pass you should run it another 2-3 times. Each pass will take about 30-60 minutes. 

  • 50hz Level 1 (0 points)

    Well, I have done the AHT twice, once in Extended Mode - and it says all clear. I will try again.


    But it does seem like the HD is okay. And even it was in trouble, that should not affect booting from the system cd, which doesn't work either, right?


    Normal boot up always ends in the blue screen loop unless I go into safe mode.

  • rkaufmann87 Level 9 (55,238 points)

    AHT isn't a perfect test it sometimes will not uncover hardware problems but it's all you have. If AHT can't find anything then I'd take it in to be professsionaly tested.

  • 50hz Level 1 (0 points)

    Does anyone else have an idea? Taking it in to be repaired is my last resort of course.