Red and green square dots?

As a follow up, I shut my computer down one night and as soon as I restarted the squares returned, in spite of having sleep disabled. I took it in to the apple store where they recommended a new video card.

So far, no squares, however it has only been several hours. At least the video card is now only $110, with a $40 labor charge.

Also, I had forgotten, but my motherboard had been replaced under warranty six months after I purchased the computer. I can't remember what was going on to require the motherboard replacement.

I will update when more time has passed.

David

Will you update us in a week or two? That would be great.

I've now been running without energy saving features for over 3 weeks without any issues. However, I'd like a solution to the issue and not a workaround. Looks like a new GPU has worked for several people now so I'm close to pulling the trigger on one.

So far, no return of the screen artifacts. Hopefully the new video card has taken care of things. I will update again if they return.

David

A week ago I decided to follow in the footsteps of a few others in this forum that reflowed the graphics card. I haven't seen a single square or had any problems with freezing since. I don't know why I waited so long to do it. I will keep you updated if the problem returns. I don't recall anybody that has reflowed their card posting that the problem has returned, so I am hopeful that this will last a while.

I'm curious to know if a "reflow" is still a relevant if the graphics card has been replaced? I mean would the replacement of a logic board and the 'graphics card' not correct the issue. Forgive my ignorance, but i've not been inside my iMac. If both of those items though were replaced by Apple and the issue is still not resolved is a 'reflow' an option for me? Also I've watched videos online and read all about it but still not certain what i would be doing. I've even done a local search but no one is willing to 'reflow'. Any and all help from those that have done it would be appreciated.

CPRodriguez, you wanna say recall, when a defected product is replaced by a new one.

Well, some time ago, they call recall for the i7 models from 2011, mine is a i5 from mid 2011.

After 3 years of normal use, it start to get worst every day. But isn't only the squares pipocating on screen, it lock and freezes, and the only way to use again, is with physical restart.

I call for phone support on Brasil, and the operator checked my serial and told me that mine isn't on recall.

Saad, because this is a malfunction, and need to be replaced.

Apple before Steve jobs, was more serious then now.

I wanna my money back. Or a new machine without bug.

3 years is a young machine. In the past, mac works for life.

This is not a user caused problem. a lot of people complain about the same defect.

This is not a cheap machine!

We need to be heard! Where is that Apple from Steve?

Where is my recall APPLE????

Shame on you!

I would imagine that a replacement should have worked unless there are some inherent issues with the manufacturing of this particular graphics card. In addition to reflowing the card I also sprayed out the dust and applied new thermal paste to the card heat sink. Maybe give those to things a shot... But then again, if you go that far you might as well bake the card for 8-10 minutes.

I guess I'm asking is the heatsink and thermals paste that people are talking about replacing not a part of the GPU that has been replaced. If both my logic board and GPU have been replaced would that replace not also have included the heatsink?

I would imagine that they replace both, but I have no idea. Maybe call the Apple Store to see what they do.

This is a Apple Problem.

They did something wrong in this project.

I will not dismantle my computer to try something weird.

Never opened it.

I wanna replacement.

And for worst, i can't stay without machine.

My work don't give me a stop.

Take it to an Apple Store and tell them what you want. No-one here can help with an exchange.

Ok then!

Thank you Csound1

i have a new 27" iMac purchased in Jan 2014. experiencing the red/green/blue square pixel problem starting the last few weeks. random. comes and goes.

anyone else with a new mac experiencing this and have a solution?

I was fighting with my iMac until last week, when the only thing i could try was installing Yosemite Developer update (now on number 4)

The Yosemite could manage better the machine, but the squares and locks on machine wouldn't stop, but minimize.

Observing the machine, i could see that it freeze more when cool then when in heavy use. Everyday i start to use it, it lock some times, even moving a window on screen, then, after some warm up, it turn into usable.

So, today i try something different and unusual.

I put a mp4 video (720p one, with around 150mb) into loop playback. so, the GPU never goes unused 100%. (never could down enough)

And it works. No more square dots, no more lock on, until now.

The thing i think is the problem, is a bad manufacture and a soldering problem, so, when it is cold, the parts retracts and this soldering get with contacts problem. But when it is hot, the things expand because, and then this bad soldering keep connected.

Until i have a new machine, and then i can put this one to recall/change to another new video board, this will solve my problem.

I hope that could help you all.

Cheers

I too am having this problem, iMac 27-inch, Mid 2010 with a 27" Display. Problem seems to be affecting only the display.