Macintosh OS/Imac boot problems


Hello Debba
I am having a lot of trouble with my IMac.
Part number: MC814x/a
Model A1312
27” , 3.1 Quad core Intel i5, 4GB ram DDR3 SDRAM. Purchased December 2011 in Australia.
•   Its current status is I have formatted the drive and am running windows 7 on it, as I could not load any mac os x system boot disks etc.
•   I can run hardware test; no errors, even on loop mode.
•   I cannot not run disk tool as that require it to boot off the disk
•   I cannot run internet recovery as that has the same symptoms as all boot disk
•   I cannot not run recovery as that has the same results as boot disks
When attempting to boot or recover I get the same results, it does show the apple logo and begins reading the disk and loading, after a short while it goes to white screen and stops. This is as far as I can get it to progress on any attempt.
I cannot run single user mode as there is no  os x system as it was formatted while attempting to resolve the issue.
Even though windows 7 is running, it is running of a generic video driver, that is because when I install the video driver the system crashes and I get a blue dump screen.
When attempting any mac os x system install options etc it freezes on the white screen. It appears this has been a gradual decline as previously I could run the boot disks and recoveries.
The original symptom before it declined to its current state was; while using the Imac it would suddenly go to a blue screen and freeze, it had large pixels. Sometimes it went to a black screen.
Once while looking into the problem I was on single user mode at the command prompt and using fsck it would come up with a message about the firewire attempt error
I have done a SMC reset and NVRAM reset.
I think it may be my video card as it appears to stall when it begins to load drivers after loading files, and the windows os refuses to load the video card drivers without crashing.
But I am unsure…
Any suggestions?

Hi, Matthew,

I'm not sure how much help I can be.  You sound quite versed in trouble-shooting your computer, for sure!  I'm a Mac person all the way and when you talk about the things you are doing in Windows, it's Greek to me.  That being said, two of my first thoughts are always - have you checked / replaced your battery and have you zapped your P-RAM?  Zap your P-RAM by telling the computer to restart and quickly holding down the Command-Option-P-R keys.  Hold them down for 5 BONGS, then let go and see what happens.

Do you have Genius Bars in Australia?  Here, in the Apple Stores, there is a section of the store where people can go, for free, to have experts help them with problems with their Apple Products.  This sounds like something THEY could do far better than I, here at a distance.  

Another thought is to get an external drive, if the one that came with the computer won't read your CDs / DVDs and attempt to begin there.

How full is your hard drive?  That can cause all sorts of problems when trying to load the system because if there isn't enough room for the information to cycle, it will just freeze up.  If you can dismantle the machine and open the hard drive on someone else's computer, you can clean it up and possibly reinstall system information while you are at it.

Do any of these things sound do-able to you?  I can talk you through some of it, if need be, but, like I said, you sound pretty capable to me.

Let me know how things go.


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Debba Robinson


AppleWorks 6, Systems up to 10.3.5, general trouble-shooting of hardware and some software.


In years past I taught computer K-8 and helped maintain Macs using sytems 7 and 8. Since 2001, I have not been working with computers daily, aside from doing my own work. I dabble in helping people out and enjoy the challenge of trying to figure out answers to your problems. Systems 7, 8, 9 and 10 are all in my repertoire now, at various levels of expertise. Please, NO networking questions.

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