Apple Releases Firmware Update to Address Screen Flickering on 27-Inch iMacs

[Padriac]

Some people are having problems and that's unfortunate. But just as many (or more) seem to have no issues, which is odd. I'm one of the lucky ones but would love to help the rest of you out. Plus, I could be on of the unlucky ones but just not know it. I think we need to be a bit more systematic, like a software developer trying to eliminate bugs.

1. Is there any systematic way to reproduce the screen flickering?
   
2. Is there any systematic way to reproduce the screen blackout? it seems to be a separate issue in that not everybody who has the flicker has the blackout. Those who have it seem to be the ones who can't have their problem solved by the firmware update.
   
3. What week iMac do you have if you have any of these problems (the first 5 digits of your serial number: 4 and 5 represent the week). The week doesn't seem to matter right now as some early weeks have no problems and some later weeks do have problems, but the later the better it seems.

My week 50 iMac seems fine in every way, and that's WITHOUT the update. Normal computer use has not revealed any flickering. I've watched Hulu full screen, checked out other flash heavy sites, messed with Lightroom and Aperture, and see no problems. Is there any better diagnostic tests to do? Is there any task or website that seems to always exhibit the flickering for those seeing the problem. Since I don't have the problem (to my knowledge) I can't really help diagnose it much, other than to check if certain tasks can trigger it.

As of now it seems most, but not all, who had the flickering issue had it resolved by the update.

 

[AidenShaw]

LED's are solid state. Good quality ones aren't even supposed to heat up.

Huh? An LED generates lots of heat - less than an incandescent or CFL bulb of the same lumens, but if you put a bunch of 5 watt LEDs together you'd better have a cooling system.

Note this underwater LED flashlight:

The AquaSun eLED Dive Light brings LED performance to the maximum, underwater. To do this we take advantage of the fact that LEDs are most intense when kept cool.

Two high intensity LEDs are attached to a heat sink which is in direct contact with the water through the front lens. This patented system cools the LEDs and allows them to burn almost twice as bright underwater.

http://www.uwkinetics.com/product/121​

 

[MorphingDragon]

Huh? An LED generates lots of heat - less than an incandescent or CFL bulb of the same lumens, but if you put a bunch of 5 watt LEDs together you'd better have a cooling system.

Note this underwater LED flashlight:

The AquaSun eLED Dive Light brings LED performance to the maximum, underwater. To do this we take advantage of the fact that LEDs are most intense when kept cool.

Two high intensity LEDs are attached to a heat sink which is in direct contact with the water through the front lens. This patented system cools the LEDs and allows them to burn almost twice as bright underwater.

http://www.uwkinetics.com/product/121​

I would like to see the specs that those LEDs are and how much juice they are supplied with. If they produce enough heat to need a heatsink they are probably running above spec.

 

[slicecom]

fI will hold off buying any 27" iMACs until they use NVIDIA. I never liked ATI and I used them a lot in building render farms in 2000 not for long though as they kept failing ever so often.

Funny, I refuse to buy any computers with NVIDIA graphics cards for the same reasons you don't buy ATI. It's all relative I suppose.

 

[Janvier]

Post Firmware Update

W89490 here.
27" i7 2.8 GHz, 8GB RAM, 2TB HD

Applied the update via Software Update, screen was still flickering a little.
Reset PRAM, NVRAM an hour ago, no screen flickering or tearing since.

Too soon to feel hopeful?

No yellow tinge, dead pixels so I can't address those issues - they seem to be hardware, anyway.

 

[Bubba Satori]

My i7 is fine

And so are the majority of 27" iMac's.

Did you survey all 27" iMac owners?

Do you have a source for that statement or is that another case of uttering a truism in order to fallaciously claim there are extremely few problems?

 

[hachre]

Funny, I refuse to buy any computers with NVIDIA graphics cards for the same reasons you don't buy ATI. It's all relative I suppose.

Same here

 

[AidenShaw]

I would like to see the specs that those LEDs are and how much juice they are supplied with. If they produce enough heat to need a heatsink they are probably running above spec.

They have two 6.2 watt white LEDs, no more detailed specs. By the way, it's not uncommon for powerful dive lights of any bulb type to either derate themselves or burn up if used in air - the water cooling is part of the design.

 

[iDocism]

W89490 here.
27" i7 2.8 GHz, 8GB RAM, 2TB HD

Applied the update via Software Update, screen was still flickering a little.
Reset PRAM, NVRAM an hour ago, no screen flickering or tearing since.

Too soon to feel hopeful?

No yellow tinge, dead pixels so I can't address those issues - they seem to be hardware, anyway.

That is a very good idea, for those who dont know how to do this...

Resetting PRAM and NVRAM

1. Shut down the computer.
2. Locate the following keys on the keyboard: Command, Option, P, and R. You will need to hold these keys down simultaneously in step 4.
3. Turn on the computer.
4. Press and hold the Command-Option-P-R keys. You must press this key combination before the gray screen appears.
5. Hold the keys down until the computer restarts and you hear the startup sound for the second time.
6. Release the keys.

Your computer's PRAM and the NVRAM are reset to the default values. The clock settings may be reset to a default date on some models.

 

[MorphingDragon]

They have two 6.2 watt white LEDs, no more detailed specs. By the way, it's not uncommon for powerful dive lights of any bulb type to either derate themselves or burn up if used in air - the water cooling is part of the design.

But LEDs dont burn up, they pop.

 

[AidenShaw]

But LEDs dont burn up, they pop.

burn: To damage or injure by fire, heat, radiation, electricity or a caustic agent​

If you don't keep the LEDs cool, they'll be burned.

 

[MorphingDragon]

burn: To damage or injure by fire, heat, radiation, electricity or a caustic agent​

If you don't keep the LEDs cool, they'll be burned.

Your use of burn suggests that a flame is involved.

 

[Lershac]

Your use of burn suggests that a flame is involved.

Why exactly do you think they "pop"? Perhaps they generate heat and melt the substrate material? LEDs get hot fella. They generate heat. If they didn't they would be 100% efficient which they are not.

 

[MorphingDragon]

Why exactly do you think they "pop"? Perhaps they generate heat and melt the substrate material? LEDs get hot fella. They generate heat. If they didn't they would be 100% efficient which they are not.

LEDs are Solid State. There is no filament to burn. They pop, like any other diode.

 

[Janvier]

That is a very good idea...

Thanks for including that iDocism.

I just got two flickers and a screen tear. Just now.
The computer has not been shut down but it has slept a couple of times since the patch yesterday.

 

[Spinnetti]

ATI video cards remind me of Audis. Great technology, looks slick. Start using it and it ends up in the shop more than I like.

Seriously, my first gen mac pro had an ati card. It worked great but whoever engineered the exhaust fan and port failed. Dust collected causing all kinds of freezes.

lol... I've got two Audi's (two iMacs for that matter!)... No complaints about Audi or Mac really, but I'd like to know more about the update. I too fear it will cripple performance. My top spec i7 works perfect, and I'd hate to apply the update and then have it work worse.

 

[Rodus]

My i5 is working perfectly so I'm not going to bother with the firmware patch until I know what it does, I don't want crippled GPU performance thank you.

 

[slicecom]

My i5 worked fine before the patch (except for the yellow tinge and dead iSight pixels) and it works fine after the patch (except for the yellow tinge and dead iSight pixels).

 

[iDocism]

Patch = FAIL!

After 2 days my iMac is flickering again. Its history and going back to Apple for a return of my 2K+, good luck to everyone else who bought one of these.

 

[MorphingDragon]

My i5 is working perfectly so I'm not going to bother with the firmware patch until I know what it does, I don't want crippled GPU performance thank you.

Fixing sync issues has nothing to do with GPU or Ram Speed.

 

[Elektronick24]

Still having flickering/Blackout problems

ok.. so i first called Apple for the flickering screen problem and they told me to bring the computer to the APPLE store for testing, which i did and they found nothing after two days!!?? Called back Applecare and told me to send the iMac 27 back to Apple for exchange and told me there was a two weeks wait for receiving the new one. I already waited 3 weeks for this one so i'm gonna wait after the holidays and maybe the wait will shorter. Yesterday morning i woke up and read through mac4ever there was a firmwaare update for the graphics. I installed it hoping this was really going to fix my computer. Unfortunately i still have flickering blackout problem. Any other reports of non functional update???

 

[iDocism]

Its weird, when I have flickering if I reboot it fixes the problem, temporarily yes but this makes me think it may be something a update could fix.

 

[PeterQVenkman]

Boy, I'm glad I didn't jump on the iMac bandwagon when it launched. Rev A is pretty risky.

 

[jabbott]

Its weird, when I have flickering if I reboot it fixes the problem, temporarily yes but this makes me think it may be something a update could fix.

The same happened to my 27" iMac once. I was playing X-Plane on it and all of the sudden it started exhibiting flickering/blackouts, even after closing down X-Plane. I rebooted and haven't experienced flickering/blackouts since then, despite running X-Plane, CoD and numerous other GPU stress tests (multiple simultaneous OpenGL screensavers, etc.). I'll try running the firmware update when I get back home, but I won't be able to tell if it truly made a difference unless the symptoms return.

 

[steve31]

My i5 is working perfectly so I'm not going to bother with the firmware patch until I know what it does, I don't want crippled GPU performance thank you.

Same here with my i7. Everything has been perfect so far so I will not mess with this firmware patch. It seems not to be fixing the problems for most anyway. It really is starting to look like a hardware problem at this point. (IMO)I really love this machine and my heart goes out to the people that are having this problem.