Help! My iMac Screen Keeps Scrambling

[Filp1010]

Hey Everyone,
My iMac mid 2011 computer screen keeps scrambling. Mostly happens when I am surfing the internet with Safari. Even if I close the browser and other applications the screen still continues scrambling every few seconds until I shut down the computer manually using the iMac Power button. Currently my IMac memory is using 4GB memory(cpu is maxed often) and when the screen starts scrambling most of the system memory is in use. Has this happened to any of you before? I have included a pic of what the screen looks like.


Running:
EL Capitan 10.11.6
27-inch, Mid 2011
2.7 GHz Intel Core i5
AMD Radeon HD 6770M 512 MB




Do you think the scrambled screen could be caused by not enough memory and lack of resources to run the computer properly or is there an issue with the computer or video card? This issue has been happening a couple of times a month for 6 months.

Also I have problems turning on the computer sometimes with the power button as I really have to push it at the right angle in order for it to power on and I have tried tightening the button by twisting it but it doesn't really help. Do you think this power button issue is related to the first one? I would really appreciate your advice and suggestions. Thanks for your help.

 

[anon(9602380)]

My first suggestion is to try a NVRAM reset. Here is a guide by Apple on how to do a NVRAM reset. Next try a SMC reset. Here is a guide by Apple on how to do a SMC reset. If either of those suggestion does not work there is a good chance your graphics card is going or it could be the power supply. But unless you have an Apple Genius look at it there is no way to confirm either. My last suggestion would be to make a Genius appointment to have it looked at. The 2011 iMac is famous for getting very warm. I had a 2011 27" i7 iMac that used to almost get to hot to touch. My 2011 started doing similar things with the screen after about 10 months old.

 

[Filp1010]

Hi Firedept10,
Thanks so much for your help. I did what you suggested and my computer seems to be running a bit smoother. During one of the first methods when my computer was restarting at the top of the white screen I saw a strip of the scrambled screen. I am not sure what that means. So far everything is working well. If my screen scrambles again I will have to bring it to Apple for repair.

Did you replace your 2011 iMac for a new iMac? If so why? I am just wondering if it is worth upgrading to a new iMac now. Thanks again.