Macbook Pro 2011 clamshell mode broken by latest software update?

I wouldn't quite call it a fix, but it's a big improvement. We're basically now to a slightly better state of compatibility than we were prior to the Graphics Update in early May, but there are still issues. I can now get clamshell to work on my 2011 MBP/2.3GHz quad-core with both the standard adapter cable and a Dual Link cable when using an NEC 2490WUXi display (for everyone's information, this is a 1920x1200 resolution LCD monitor). The switching on of the monitor as the system is brought up from sleep is glitchy, in that waking from sleep produces a quick flash of the display, then blank for a few seconds, and then the display works properly. Most importantly it works even with Low Power Management (i.e. deep sleep) activated on the monitor, and at least there isn't any more trouble switching between using the laptop display and using the external monitor with one or other of the adapters. The glitchy turn-on of the display should not happen, and indeed does not with a smaller Dell monitor with 1280x1024 resolution. The Dell display takes longer to go into, and come out of, sleep than the NEC so I think synchronizing with that timing is part of the problem.

It's still worth noting that the computer will not use the integrated graphics to output a signal to this monitor; only the Radeon chip, which I think is ridiculous. Perhaps Apple are still struggling with the Radeon and/or Intel drivers. In any case, I'd much prefer it if they'd allow the integrated graphics to be used. Obviously you need the discrete chip for things ranging from gaming to running color calibration software (for one thing, NEC's Spectraview software won't run a color calibration from an Intel integrated graphics device), but for routine use I'd prefer the lower heat output of the integrated chip, not least because it will help the durability of the computer and especially the battery. I can have that with a big HD display on a 13-inch MBP, so why not the 15?

I just updated to OSX 10.6.8 and am pleased to say that clamshell mode is now working perfectly with my LG monitor! Woohoo! It now comes out of sleep and works exactly as it should.

I'm happy to report that with OSX 10.6.8 the problems I had under 10.6.7 with clamshell mode are gone.

All appears to be working as expected with my Dell 2709W & 2011 MBP 15".

I've not confirmed DecisiveMoment's issue with the Intel/Radeon card use (how can I check?)

If he/she is right, I'd agree it's a bug. I'd like the Intel card to be used where it can be also.

Great news! The 10.6.8 fixed the problem!!

Still not reliably fixed as it turns out. It looked promising (if glitchy) for me yesterday but this morning after the computer was in sleep overnight I was not able to bring up a display with the monitor attached, either the external display nor the built-in one. I had to reboot.

So there are still serious problems.

You can see which chip is running which display by going to the System Profiler and bringing up Graphics/Displays. The 15 and 17 inch laptops are all forced to use the Radeon for an external display as I understand, which is crazy. You'll be able to choose Intel 3000 or Radeon and if you're in clamshell you'll see the monitor information come up under the Radeon but nothing come up under Intel 3000.

Well, I guess I spoke too soon. I thought I had tried everything. I manually put the system to sleep and it would wake up fine, but after I walked away last night and came back this morning, the system would not wake up. Same results as before the update... Everything seems to work fine, except when I walk away and the system automatically enters sleep, then it will not wake up.

And, just as the others posts state, when connected to an external display, the internal Intel 3000 chip is disabled.

Did the upgrade this morning ... I am sitting in my most difficult office (I have three) and the clamshell mode came up (more or less) correctly the upgrade <s>

On May 6, I posted that I experienced problems with sleep/wake in clamshell mode immediately after installing the following:

MacOSXUpd10.6.7MBPEarly2011

Mac Software update 1.4

And a May 5 Firmware Update

I had opened a case with Apple support but nothing improved the situation over the past 7 weeks. After Installing the OS X 10.6.8 upgrade on Thursday, June 23, there was still no improvement.

But after installing the Thunderbolt Firmware upgrade on Tuesday, June 28, Clamshell sleep/wake worked immediately and upon a second attempt. I am not 100% prepared to say the sleep/wake issue is fixed, but it is currently 2 for 2.

As to other issues, such as which graphics processor is being used, I cannot say. My primary issue was Clamshell mode.

I can also confirm that the latest firmware update solved the problem on my system.

I'm having problems with the sporadic clamshell mode working off and on. My '11 MBA 11" powers down the internal and external monitors when I place it in clamshell configuration. The machine is still running, you can hear sound and the fan spinning. However, the external display won't power on. This is very frusterating indeed.

Have you upgraded to 10.6.8 ... the problems you describe drove me nuts under 10.6.7 ... 10.6.8 have solved them for me <s>

I FOUND OUT WHAT IS CAUSING MY EXTERNAL MONITOR NOT TO WORK WITH MY MBA 11" 128GB.

When I first hooked up my 23" LG my MBA worked fine in clamshell config. However, I noticed once the system went to sleep and I powered it up, my external monitor would not power up. I realized this issue began when I adjusted the resolution settings between my MBA internal screen and my external monitor. I have found that some configurations between resolutions will allow my MBA screen to work and not the external, then when I place the MBA in clamshell mode, the external monitor will power. The problem I'm having is sporadic monitors being powered depending on if the system is in clamshell configuration and what resulutions are selected between the two in display setting.

I placed my two default resolutions to

External: 1152x864@75hz

MBA: 1366X768

I hope this helps some of you having problems related to mine.

Also, I am running Lion 10.7 on the new MBA with thunderbolt port. Sorry for forgetting to mention that.