Strange iMac Issue #2: Boots to white screen with cursor...

[Krynn72]

I've got yet another odd iMac, seems they love causing me trouble.

We've seen the "white screen" issue before, but not like this. Basically the computer powers on, chimes, shows the apple logo and the loading bar. Then screen goes pure white with the black mouse cursor. After a day of scratching my head and trying different things (I'll list below) I found a work around to get the computer to work. Basically when that screen comes up with the mouse cursor, if I click the left mouse button, and then press enter, the cursor will change to the spinning umbrella icon, and after a couple seconds it proceeds to the user login screen. From there, it works as expected.

Computer details:
27" iMac Late 2009 A1312
OSX 10.10.4

-I've tested the HDD and it comes back ok with Extended SMART tests.
-I couldn't get Parted magic to load, it would go to the EFI boot menu and then the screen would go black and not load. I've had this issue on other Macs too, and don't think much of it
-I loaded into the recovery partition and disk utility's verify disk found no issues, but it found and fixed many permissions.
-I've done the SMC&PRAM Resets.

I installed the latest OSX updates when I figured out how to log in, and when it automatically restarted it came straight to the login page like you'd normally expect. I then manually restarted it, and the issue came back. It also happens if I do shut down and power it on again via the button.

I'm thinking its going to be a N&P or live with it type of deal, but do you guys know anything else I can try?

 

[altrenda]

Does it do it when you start up in Safe Mode?some boot up issues can be fixed by a safe mode start then a reboot.

 

[cyabro]

Make yourself a USB OS X bootable drive and then you can use that for testing.
Boot from that and see if the problem still exists then you'll know of it's software or hardware.

 

[Markverhyden]

Make yourself a USB OS X bootable drive and then you can use that for testing.
Boot from that and see if the problem still exists then you'll know of it's software or hardware.

^^^ This is highly recommended in the OS X world. Let's you learn much more about the issues at hand. It's easy to slice up a USB drive and load up several different versions. To be honest it could easily be an HD problem. False positives/negatives are common. For grins I'd also re-seat the RAM.

 

[Krynn72]

Does it do it when you start up in Safe Mode?some boot up issues can be fixed by a safe mode start then a reboot.

Booted fine into safe mode, but issue persisted upon restart.

^^^ This is highly recommended in the OS X world. Let's you learn much more about the issues at hand. It's easy to slice up a USB drive and load up several different versions. To be honest it could easily be an HD problem. False positives/negatives are common. For grins I'd also re-seat the RAM.

Reseated RAM (and held down power button with ac cord out to discharge completely). Issue persisted.

Unfortunately for science, the customer was eager to get it back, and decided to live with the workaround. Never got to figure it out.

Make yourself a USB OS X bootable drive and then you can use that for testing.
Boot from that and see if the problem still exists then you'll know of it's software or hardware.

Does this mean just installing OSX to a flash drive? I have the installers on a external hdd, but they're not like a linux bootable in that you get the fully operational OS.

 

[altrenda]

When you have access to a working Mac, use something like Carbon Copy Cloner or Disk Utility to make a bootable clone on an external drive.
As said above, its very useful to be able to boot and run the system to determine if its a hardware or software issue. And there are certain tasks that can't be performed on the internal drive if its the boot drive, like rebuilding the volume structure.
I have a copy of Techtools Pro to Go on a flash drive that I use for the same thing. I've fixed many nonbooting Macs this way.

 

[Markverhyden]

Does this mean just installing OSX to a flash drive? I have the installers on a external hdd, but they're not like a linux bootable in that you get the fully operational OS.

When you have a Mac handy. Get a USB HD or a larger thumb drive, say 64 GB. Use Disk Utilities to carve out a partition, naming it as you wish, for each version you want to install. Obviously you need the installer images for each one as well. Then launch each installer image from the Mac and point it to the respective partition on the HD/thumbdrive. You will end up with a fully functional and bootable OS install on each partition. You can then plug the HD/thumbdrive into the target Mac. Power up the machine holding the option key down to select your image. Apple has always had a LILO'ish/GRUB'ish boot loader, even back in the pre-OS X days.

Can you do all installers? No. The machine you are using controls how old of an image you can install. You can start with the image that came with and anything newer. So if you have a late 2011 machine you can start with 10.7 and go forward. But you will not be able to use 10.6. Another observation. When I've done this using a Mac that has FileVault2 enabled I have a lot of problems with the installer not continuing after the installer reboots.

 

[E Bell]

Sounds like he might have a problem with one of the applications starting at boot that was bypassed while booting into safe mode.