Something Very Bad just happened to iMac

[Rhobes]

Hi All-

I have a 2010 27" iMac.
Out of no where I started getting pixelations within the pages on all tabs & windows opened with webpages. The pixelations immediatly got very bizarre, all kind of squares, rectangles, horizontal & verticle lines, you name it you could find it, all jumbled up on all tabs. There was no noise associated with it.

I restarted, no help. I shut down, then restarted, no help. I left unplugged a few days then restarted- the Apple came up with download bar that progressed to just over half the bar then just a white screen appeared, empty & would remain indefinite without any odd noises. Never got anything to appear except white blank screen (with Apple & progress bar each time to 1/2 before dissappearing).

I then restarted with option shift R and with disk utillity did first aid to everything there at least 5 times each. Still same white screen appeared.I unplugged awhile redid first aid and restarted and got a screen saver pic with multiple black squares that dissappeared but left the screen saver pic alone with several pixelated horizontal lines evenly spaced (about 2' apart) running length of screen. I redid the same things mentioned here but have always only got the white screen since.

Any idea's? Has my HD crashed? What simple steps can I do next?

P.S. I do have a time machine backup available from a couple years back. I have nothing attached to iMac now (no peripherals). I have only used iMac last two years to check emails until I finished remodeling house I moved into.

Thanks for any suggestions-

 

[tyc0746]

Could be the graphic card.

Try running the hardware test to see what it says.

 

[Fishrrman]

After 9 years, it sounds like the graphics may be giving up the ghost.

My opinion is it's not worth putting $$$$ into a 9-year-old iMac.

Time to start shopping for either a new one, or perhaps a 2017-design from the Apple-refurbished online store.

Also worth considering is the 2018 Mac Mini...

 

[Rhobes]

Thanks Fishrrman & tyc0746 for your suggestions-

I ran the quick and extended versions of the Apple Hardware test, both results were: "No Trouble Found". I believe that indicates not a hardware but a software problem exists. I'm hoping to come up with a good idea what is going on before looking into something new, repairs, or bringing into an Apple Certified shop.

Before the Hardware test I followed most of the steps from: Appletoolbox.com "Mac Stuck on White Screen?" Some of the items, eg. Terminal Commands were not recognized and verifing/repairing permissions could not be done. I ran first Aid via disc utility and reset PRAM/NVRAM. I did not do any further things other then First Aid. I have not erased or re-installed Mac OSX, may do as a last resort or leave for an Apple Tech.

Additional info to my 1st post, first paragraph. I can now get into my iMac account by doing a SAFE BOOT, this is the only thing I can do, it brings up the accounts to which I select mine. Without doing the Safe Boot it always goes to a blank white screen. I've done many restarts, shutdowns, unplugging iMac & no combinations change this except holding "SHIFT" key down on power up.
I only open 1 window, multiple gives the background clicking (which you normally hear) but excessive to the point you expect it to crash; especially if you try to move a couple windows on the desktop.
Moving a window causes horizontal, vertical or both lines to ripple through the window. Also upon movement you get flashing geometric outlines, sometimes black squares. As the screen saver pics transition, I get horizontal light flashes- it should be a smooth unnoticed transition to the next pic. I can scroll what's in my window without any visual problem, yet it is somewhat jerky. When typing there is a slight pause before the letters hit the page- annoying. Increasing or decreasing window size by dragging a corner causes total break-up of the page & window & delay in getting it put back together as a viewable/readable page.

If anyone has further suggestions please post. I have a Time Machine back-up but hope to possibly diagnose the problem before attempting it. I also cannot upgrade beyond 10.11.6 (El Capitan) because my Photoshop CS2 will not work above it.

Thanks-