iMac won't boot up properly anymore

[rhuarc3]

So my iMac 27" just made a really loud noise while playing music using pandora app. It's tough to describe almost like a power surge to an amp when you shut it down mid riff.

I had installed 8gb additional ram about 2 weeks ago. Hope that's not what caused it. It's been running fine until I updated the adobe air because the pop-up said to for the pandora app. Now I can't even get it to startup properly. The one time it did start all the way up I tried to use time machine to undo the update hoping that would fix issue and Mac just shut down ( powering off not just sleep). Now the Mac freezes on the white screen with the apple.

I know this might be hard to understand but I'm not a computer genius so it's tough for me to explain. Any help or suggestions? If I can't figure it out today, I'm bringing it in to the Genius Bar. Thanks.

Running current version of ML. 12gb ram total. I think it's the i5 chip. 1TB hd about 1/2 full. Mid 2010 model.

 

[benthewraith]

So my iMac 27" just made a really loud noise while playing music using pandora app. It's tough to describe almost like a power surge to an amp when you shut it down mid riff.

I had installed 8gb additional ram about 2 weeks ago. Hope that's not what caused it. It's been running fine until I updated the adobe air because the pop-up said to for the pandora app. Now I can't even get it to startup properly. The one time it did start all the way up I tried to use time machine to undo the update hoping that would fix issue and Mac just shut down ( powering off not just sleep). Now the Mac freezes on the white screen with the apple.

I know this might be hard to understand but I'm not a computer genius so it's tough for me to explain. Any help or suggestions? If I can't figure it out today, I'm bringing it in to the Genius Bar. Thanks.

Running current version of ML. 12gb ram total. I think it's the i5 chip. 1TB hd about 1/2 full. Mid 2010 model.

If you hold down the option key, can you successfully boot into Recovery?

 

[rhuarc3]

ok so i let it sit powered down for about an hour and then started it up. seems to be running fine. promptly deleted the pandora app. haven't tried music yet but am going to run some diagnostics first. hopefully it was just the app. and not something more serious.

mild panic has settled down. thanks for quick response.