27-Inch iMac Firmware Updates Address High Processor Usage, Display Backlight, and Target Display Mode Issues

[Darkroom]

Can you talk more about your 'mura effects' on your screen? What exactly do you mean by that?

this site gives a good description of mura effects. the most common type i've experienced on all of my screens (in varying degrees) for the 24" LCD iMac, according to this page, is type 3, which most people simply refer to as screen bleed.

my screens were not replaced because of mura effects or color casts, although one of them could have been as it was shockingly awful. they were replaced because my icons, windows, etc. left strange burn-in/ghosting effects on the left side of the screen after only a few hours. this happened exactly the same with all of the screens, so it became apparent that the problem was with the computer and not the screens, although the severity of the burn-in/ghosting effects was clearly attributed to the quality of the screen.

of interest, Mura is japanese for unevenness.

 

[Brile]

Does this really work?

I have the Mac os X 1.6.3 and my 27 inch iMac bought in Oct 2009 cannot tale in the software update, do it need to be a Quad core or can it also be on a dual core, shouldn't the apple/back light work anyway?

 

[NGL]

so you're current 27" iMac screen is without defect?

Indeed. It was quite the process to find this machine though.

-Nick

 

[Brile]

Is this fix not compatible with the Dual core 27 inch Mac?

Is this fix not compatible with the Dual core 27 inch Mac? Does anyone know why my backlight does not work and the Firmware fix does not apply when i try to download it to my dual core machine?

 

[Darkroom]

Is this fix not compatible with the Dual core 27 inch Mac? Does anyone know why my backlight does not work and the Firmware fix does not apply when i try to download it to my dual core machine?

About 27-inch iMac EFI FW Update 1.0: The update is recommended for all quad-core Intel Core i5 and Core i7 processors 27-inch iMacs.

not sure what you mean by your backlight not working. if your computer is broken it's still under warranty. if you have apple care you can get onsite repair, otherwise just take it into the apple store or authorized repair shop.

 

[Brile]

About 27-inch iMac EFI FW Update 1.0: The update is recommended for all quad-core Intel Core i5 and Core i7 processors 27-inch iMacs.

not sure what you mean by your backlight not working. if your computer is broken it's still under warranty. if you have apple care you can get onsite repair, otherwise just take it into the apple store or authorized repair shop.

So the apple on the back should be lit with other words, I am new to Mac so... ?

 

[G-Force]

The Apple logo only lights up on MacBooks, your iMac is working fine.

 

[Darkroom]

So the apple on the back should be lit with other words, I am new to Mac so... ?

no. the apple logo on the back of the iMac does not light up like it does on MacBooks.

 

[Brile]

no. the apple logo on the back of the iMac does not light up like it does on MacBooks.

So what does Display Backlight mean then?

 

[MorphingDragon]

So what does Display Backlight mean then?

A backlight is a plane of fluorescent/LED lights just behind the LCD matrix of the screen, providing light.

 

[mitch969]

Software update can not find anything new.
I tried to update it manually but I get this message (pic).
I am sure that i have downloaded the right file from the site http://support.apple.com/kb/HT1237
(ver. 1.54f36).

I have noticed that ver.1.54f36 and ver.1.53f31 have the same link to the same download site. Is it mistake or is this normal?

Thanks.
m.

The same error msg appears if I try to manually update the latest EFI.

Hello,

Looks we are not alone, have a look here on Apple Discussions : http://discussions.apple.com/thread.jspa?threadID=2401061&tstart=0

I contacted Apple and I had to explain three times the story. They all wanted that I bring back the iMac to an Apple Store, I refused. I just asked to reflash the SMC firmware manually but they didn't know how to do this... The conclusion was that a tech will come on Monday to have a look and reflash the SMC firmware. After talking to the tech to fix the appointment, he explained me that he has no tool to reflash so Apple asked him to change the logic board. This is crazy to replace the hardware if it is just a software issue.

So in the meantime I found something interesting I would like to try. On a forum about issues with an SMC firmware with MacBook Pro, a guy explained that you can reflash the firmware manually if you extract the files needed in the update package (using Pacifist) and if you install Refit. You can have a look on the post number 25 in the link below :

http://forum.onmac.net/showthread.php?t=726&page=3

First I will backup all my data with time machine and reinstall the OS in the case of something will go wrong.

I will also have to decide which file to flash because there is two files in the SMC update (k23.smc and k23f.smc). One is probably for i5 logic board and the other for i7 logic board.

If you want to try this, do it at your own risk and please report here your findings.

 

[terraphantm]

Yes, it's solved

I can use my 27" iMac as a screen for my Mac Pro

Cheers

You have a 5870 in your mac pro? You sure it's not a 4870 which was always compatible with the 27" iMac?

 

[NGL]

I see some people are having problems with their fans after the SMC firmware update... is there ANY reason to do this update if you don't plan on ever using your iMac as a display for another computer? I'd rather not risk it if that is indeed the only function of the update, and if it's not a requirement for future firmware updates.

-Nick

 

[mitch969]

Hello,

Looks we are not alone, have a look here on Apple Discussions : http://discussions.apple.com/thread.jspa?threadID=2401061&tstart=0

I contacted Apple and I had to explain three times the story. They all wanted that I bring back the iMac to an Apple Store, I refused. I just asked to reflash the SMC firmware manually but they didn't know how to do this... The conclusion was that a tech will come on Monday to have a look and reflash the SMC firmware. After talking to the tech to fix the appointment, he explained me that he has no tool to reflash so Apple asked him to change the logic board. This is crazy to replace the hardware if it is just a software issue.

So in the meantime I found something interesting I would like to try. On a forum about issues with an SMC firmware with MacBook Pro, a guy explained that you can reflash the firmware manually if you extract the files needed in the update package (using Pacifist) and if you install Refit. You can have a look on the post number 25 in the link below :

http://forum.onmac.net/showthread.php?t=726&page=3

First I will backup all my data with time machine and reinstall the OS in the case of something will go wrong.

I will also have to decide which file to flash because there is two files in the SMC update (k23.smc and k23f.smc). One is probably for i5 logic board and the other for i7 logic board.

If you want to try this, do it at your own risk and please report here your findings.

Issue solved. I flashed the SMC manually using refit.

If you have the same issue you can PM me.

 

[matej555]

@mitch969

I have followed your step by step instructions and it worked like a charm.
Thank you very much. I owe you big time.

Thanks.
m.

Edit:
Do you have StartupSound.prefPane installed? I suspect this could be the cause for failed initial install of software update.

 

[mitch969]

@mitch969

I have followed your step by step instructions and it worked like a charm.
Thank you very much. I owe you big time.

Thanks.
m.

Edit:
Do you have StartupSound.prefPane installed? I suspect this could be the cause for failed initial install of software update.

You're welcome !

No I don't have startupsound installed but I had two external harddisk connected. Apple said that you must disconnect all stuff before upgrading the SMC firmware. It could also be that I was running my system in 64bits, perhaps there was a compatibility issue with that.

 

[jazz1]

HOLLY MOTHER OF GOD!!!!!!!

This update scared the hell out of me!!

When rebooting after the update it made the BIP sound (i suppose like everyone else) and the only experience i had with this kind of sound was in a iMac G3 when installing incompatible memory. Jeeeezzzzz.

BTW, is it me or the monitor looks a little bit more bright / better looking / uniform white???

Better than the screeching brakes and car crash sound my iici used to makecwhen RAM wasn't seated.

 

[mermaid2010]

I see some people are having problems with their fans after the SMC firmware update... is there ANY reason to do this update if you don't plan on ever using your iMac as a display for another computer? I'd rather not risk it if that is indeed the only function of the update, and if it's not a requirement for future firmware updates.

-Nick

Can anyone please answerthis question as I also am concerned as to whether I should download this update, it sounds scary , please advise.......

thank you