MacBook Pro screen blinks

My new MacBook Pro display screen is blinking or flickering every few minutes now. I've only noticed it when I've switched to the integrated 9400M graphics processor. I don't recall seeing any blinks when using the discrete 9600M GPU. Usually it is only the top half or so of the display that blinks or flickers for a split second. Anyone else having the same problem?

MacBook Pro (Late 2008), Mac OS X (10.5.5), tv, iPhone, iPod Touch, et al

Posted on Nov 28, 2008 5:28 PM

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1,610 replies

Apr 1, 2010 10:56 PM in response to munchnstuf

Just had my late-2008 MBP replaced with a new one by Apple, after they replaced a motherboard and a display assembly in two repair attempts. The flickering seemed to get progressively worse after each repair, and on the third trip to Apple Store, it was so embarrassing that Apple held on to study the computer, only to offer to replace it with a brand new MBP the next day.
Don't count on the replace parts too much, whether it's the motherboard or display, they're likely to be some recycled part taken from a faulty MBP that somehow passed Apple's hardware test. Be persistent and patient, and eventually you will get your product replacement.
The whole process, since I first brought it in, took a mere one and a half week. To Apple's credit, their repair turnaround sure is quick.

Apr 2, 2010 8:37 AM in response to munchnstuf

Just wanted to add my experiences with this... I took my MBP (15" Unibody, late 2008) to my nearest service centre (still a three hour round trip) and referred them to this video:
http://www.youtube.com/watch?v=Zxcnwi_mxK8

They replaced the logic board under warranty, which disappointingly did not help. I took it straight back there the next day, they apologised and ordered another new logic board immediately, but then phoned up the next day to say that an Apple engineer had told them this behaviour is "normal" for this era of MBP, so they'd already sent back the new logic board and wanted me to collect the laptop unchanged!

Obviously it is not normal behaviour for what is supposed to be a premium computer, and after some complaining to Apple the store was told to replace the RAM and give it back... Again, no help, in fact the flickering seemed worse. Very disappointing. Four 3-hour round trips wasted.

I complained again and Apple agreed to have it collected and sent elsewhere for another logic board replacement. Over a week later, I get it back and the flickering is gone, at least for the three days I used it: unfortunately the headphone socket on the new logic board was broken, so I sent it back for yet another repair.

Logic boards used: 3
Logic boards with serious faults: 3
Weeks without my MacBook Pro: 4 and counting
Chances of next logic board fully working: ?

FWIW, I can't say I noticed any patterns in the blinking. It happened after hours of use or immediately after coming out of sleep, whether it was hot or stone cold, when typing / scrolling with the touchpad or not touching the machine at all, CPU busy or dormant, USB devices plugged in or not... Perhaps more often when it was hot... But generally random.

Apr 9, 2010 5:58 AM in response to tahitibub

hmm, sure that the blinking is a hardware failture?
I've got my new Mini Displayport to HDMI adapter today and connected it with my blinking mbp and my 46" Bravia LCD. While my MBP-display was blinking all the time, the mirrored Display on my Bravia LCD was perfect without any kind of blinking or flashing. That indicates that the 9400 chip is nonfaulty or what do you think?

Apr 10, 2010 5:38 AM in response to munchnstuf

Just thought I'd chime in.

My Macbook Pro's mobo was replaced because the headphone port died, it probably shorted out. Within a week, i had to replaced that Mobo as well because it gave kernal panics.

Then i noticed the flickering issue as well. My first mobo may of also had the problem, but i can't recall having it back then. Most of the time, running leopard back then. It's only occurs when using the 9400m, at low brightness in between mid-brigthness and lowest setting. At lowest setting, it doesn't flickr either. No issues when running on the 9600 m, or when I use SMC fan control to increase cooling of the mobo. So it may very wel be an hardware issue, or maybe it is software.. I dunno.

Hopefully Apple will take this issue seriously, they MBP pro's aren't 500 dollar netbooks...

Apr 10, 2010 11:04 PM in response to munchnstuf

I'm guessing the pulsing or pulsating backlight effect has something to do with the timed flickering of LEDs to simulate dimming. If it's only happening on the "Better Battery Life" setting (not High Performance), it's probably because of the competition of power among devices is greater and retards the timing of the LED flickering just a hair.

Turn the brightness up a little bit if you're running on Better Battery Life and it should go away.

PS: Do a search on other LED-based notebooks (ie. Sony, Lenovo, etc) and they have the same complaints about low brightness on LED displays.

Message was edited by: Oso Grande

Apr 12, 2010 8:00 AM in response to CT

I just want to update my previous comment.
My original observations - which I stand by - were over a several day period since upgrading to 10.6.3.
I had not rebooted since the upgrade (it's a mac, I rarely have to reboot). But today I rebooted to fix a little glitch (display sleep wasn't working). Now the temperatures are waaaay down - probably lower than before 10.6.3, although it's hard to be certain. I waited quite some time to be sure this lower temperature was stable.

Although I have seen the blinking once or twice, it is almost non-existant compared to before 10.6.3.

charlie

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MacBook Pro screen blinks

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