Wtf is wrong with my iMac?

[aPple nErd]

Ok my iMac has been to the apple store numerous times because of freezing and beachball and white and black screens. Well don't even get me started on the genius bar experience. The problem is till happening. Should I wipe the hard drive, or is the logic board going out or is the monitor cable loose? Any help is appreciated.

 

[simsaladimbamba]

Can you tell us what exact iMac with what specs and Mac OS X version you use? And what did Apple find, when they had your Mac? Tried another store?

"How to maximise your MacRumors troubleshooting experience" created by mad jew in 2006​

 

[aPple nErd]

Mid 2011 iMac 21.5 inch 2.5 ghtz core i5 4gb ram, 500gb hdd, and osx mountain lion 10.8.2

 

[simsaladimbamba]

Mid 2011 iMac 21.5 inch 2.5 ghtz core i5 4gb ram, 500gb hdd, and osx mountain lion 10.8.2

Tried more RAM and 10.8.3 yet?

Open Activity Monitor and go to the System Memory* tab and look for Page Outs and Swap used and report back.

* Mac OS X: Reading system memory usage in Activity Monitor​

Open Activity Monitor and select All Processes and then sort by CPU to show you the process(es) slowing down your Mac or speeding up your fan(s) or causing more heat.

Using Activity Monitor to show you CPU and RAM usage​

 

[aPple nErd]

It's been happening since 10.8.1 the reason I think a cable is loose is that when I had the fans replaced, the Mac was on 10.8.1, and after that, the problems started. I'm thinking maybe the cable got loose a little bit when the technician was fixing it. But it ran fine untill 10.81, after it got ome from apple store. Also, it mostly happens when I'm switching users, or putting it to sleep, or waking it up.