LukeD, run the Linux Live CD and report back which GPU is being used. It is my understanding that a test drive operating system like that would only have basic gpu support to give it the broadest range of system compatibilty and would not take full advantage of both the 9400 and 9600 until a full system specific installation had occured and the appropriate drivers were in use.
That said, I have experienced this issue with 1) 10.5.5 through 10.5.8, 2) 10.6 through 10.6.8 3) 10.7 through 10.7.3 and finally even on my developer account copy of OS X 10.8. The issue remained even after clean installs, an installation of a brand new hard drive and a clean install to the hard drive and numerous attempts to clear it by resetting the PRAM.
Not a single logic board replacement had fixed it.
Logic boards should only be replaced for extreme circumstances.
Hate to correct you, but the 3rd replacement of my MB 5,1's (Original late 2008 model, currently running 10.6.8) logic board actually seemed to fix the flickering issue. For me, the issue started after I upgraded to Snow Leopard. I originally assumed it was software based, but I believe there were people still running Leopard who also experienced the problem.
I eventually had it serviced (replaced logic board), then again after it started flickering after a few days (again replaced logic board, and the display), and then a third time after a few days (again, the logic board was replaced). The last replacement was performed in May, 2011. My AppleCare warranty expired in Oct, 2011. Since the last logic board replacement, I have not once experienced the flickering. I am VERY disappointed about this, to be honest. I was really hoping to get a replacement MB Pro when it started again after the 3rd repair. But, it never started flickering again! I'm both happy that it's been working properly, but still disappointed, as I believe that anyone who's had to have a very expensive laptop serviced 3 times for the same problem should be given a new one, even if it doesn't happen again. That would just be good customer treatment on Apple's part, and would really ensure loyalty from a lot of people who have considered leaving for other shores based on how they've seen the customer base treated.
Sorry for the long winded explanation. I've been sitting on this story and should've written about my experience a while ago. I also applied the EFI update, but was hesitant to since I wasn't sure it wouldn't reintroduce the problem again!
But, so far, so good. The update applied cleanly. Of course, I had that mini heart attack when it made the loud startup sound, but all was well after a few minutes. So far, no flickering.
Well, just seen the EFI update and I was kinda esitant in applying it as my third logic board replacement had solved the flicker issue(been almost an entire year without flickers of the screen running on the 9400).
One thing I found interesting is that recently I started writing programs using CUDA on the 9400: what I found out is that when I mismanaged the memory stuff(pointing to an unallocated memory region or errors like that), while in general on the CPU when you do that kind of mistakes you usually get a segmentation fault or a crash, on the GPU i got a blink on the screen(fullscreen blink, bottom half blink, top half blink) so maybe this could be somewaht related and indicate a software issue(but then again a logic board replacement solved my issue).
Hey Guys, i also got the problem... Already went to a Premium Reseller and after two of "checking" my MacBook Pro 5,1 15" Late 2008 they told me, thay can't decect the problem on my Mac. They want my to record the blinking...
Full of happieness i installed the EFI update and ....
... 2 hours later i've got the frist blinking...
... day later second blinking....
Problem is still there....
Well, by no means is the EFI update going to be a one size fits all fix. There are bound to be systems that have the same issue but it is caused by a different reason. I recommend resetting your PRAM, just in case it has corrupted settings that are causing the issue to still "exist". I would also do a full calibration of your battery. A strange idea I know, but I found that (on my system anyways), recalibrating my 4 month old battery after the EFI update brought me from a average life of 45 to 60 minutes of use to a recent average life of almost 4 hours of life. I admit that it is unlikely, but it is possible that whatever was fixed by the EFI update could also have been the problem that was responsible for the short battery life often found on this model.
For those that are curious, I am now in my 48th hour of flicker free operation since I downloaded and applied the EFI update.
Wich, you could be on to something there. I used to have a late model 15" PowerBook G4. It had suffered from the logicboard design flaw where the lower memory slot would fail and could not use see any so-dimm installed. Someone had found a workaround that could be applied using open firmware commands, but it had a tendency to cause a screen flash (and system crash) as you were still technically trying to write to unallocated memory.
I tried to install this software, but it showed an alert that "This is software is not supported on your system" I am using a MacBook 13-inch, Aluminum, Late 2008,
Processor 2.4 GHz Intel Core 2 Duo
Memory 4 GB 1067 MHz DDR3
Graphics NVIDIA GeForce 9400M 256 MB
Serial Number W89152C18QU
Software Mac OS X Lion 10.7.3 (11D50b)
The Graphic/Displays information is like this:
NVIDIA GeForce 9400M:
Chipset Model: NVIDIA GeForce 9400M
VRAM (Total): 256 MB
Vendor: NVIDIA (0x10de)
Device ID: 0x0863
Revision ID: 0x00b1
ROM Revision: 3385
Resolution: 1280 x 800
Pixel Depth: 32-Bit Color (ARGB8888)
Main Display: Yes
Is this a graphic driver problem? I will be appreciated if you can help me on this(or provide some instructions), I am hardly to use this cmputer after 30 minutes(it is blinking too frequently?)
I have a Macbook Pro purchased in late 2011 that started with the flickering screen. I have all of the latest updates, did the PRAM reset, and reloaded Lion 10.7.3 via the download. The problem persists. I spent the better part of the last two days reading online post and trying to figure out something to make the problem go away. Changing screen resolutions did not solve the problem either. I found closing the lid as if to make it go to sleep and then opening the lid will make it stop blinking for a few minutes and then it is back to it again. Where is Apple support? I'd just like to add that I was a PC guy for the longest time. I came over to the "Dark side" about 3 years ago. One of the reasons was I thought Apple produced superior equipment. I am beginning to wonder. I know the laptop is still under warranty. I will still take it in to the Mac Store but I have read enough post to see it is unlikely they will do anything to help.