I've been skimming multple threads on this same issue all day with no cure yet.
I have a 27" mid 2010 3.2 ghz imac. I bought new memory and thought 'Cool' I'll buy mountain lion and update and have a nice new system to work on. (as of right now, new memory is in the packaging and I'm back to original memory, to make things less complicated)
I installed the ram, and couldn't get the computer to boot. Grey screen with apple, but no progress wheel. So I switched the ram around in many different slots thinking juggling might help. Now I can get to my login screen but only the wallpaper shows. I have to guess where the password entry is, and type the password, then I can log in. Strange right? It get's even weirder...
So I open up Final Cut Pro X and Adobe Bridge to keep working on my current projects. (I left off this morning before the update)
Now they all crash. Here's a list of programs I've tried:
I've deleted plists, ran Onyx, disk utility, etc. Nothing helps remedy this. Now I try to redownload Mountain Lion and it almost finishes and crashes. So it won't let me do that, no matter how many times I restart, sign out of apple ID. Sorry if I'm leaving anything out, I've been at it for 7 hours now, and my brain has started to fizzle out.
I'm running 10.8.2 and it says I have an update. So it asks me to restart so I can install the supplimental 10.8.2 update, but after restart I get to the invisible login screen, and nothing prompts the installation. So I locate the manual download file via apple support site. I download it, and when the Diskimage opens in finder, finder crashes and relaunches. Is this a cruel joke? Also I can't run Apple hardware test. Even if I try the internet boot option apple-D (I forget which key exactly) Both boot key combo's tell me that its not supported with this model!
I never got any install discs because this Imac was a "Coop" as they call it in the apple store. My last iMac had classic display problems with screen burning, dark lines, patches, and uneven lighting so they finally replaced my computer... but gave me an Imac without a box, cables, keyboard, discs... NOTHING! This was over a year ago but after an ongoing battle to have them replace this one for having the same issues with the display I decided I'll put up with a faulty garbage display and just use my external monitor. Now I'm having this issue. So how can I even run AHT when I don't have the original discs?
I'm guessing it wasn't a good idea for apple to stop making install discs... now we have a fresh OS that resembles an iphone and has a laundry list of problems. I just can't wait to setup my genius appointment and hear "Oh wow... we haven't heard this problem yet' even though there are hundreds of threads that explain my exact issues. What gives?
Any help would be greatly appreciated. I'm sorry if I come off like a hot head, I'm just frustrated and the real thorn in my side, is that I'm used to working on computers as part of my career so I'm not just some facebook/twitter user complaining about hiccups here. These are real issues and quality control has gone down the bucket.
Again sorry if I left out any important info. I'll keep refreshing this page in hopes to hear some ideas.