i7 MBP and Snow Leopard Graphics Update
 

Hi,

I have a brand new MBP i7 with all current updates (so 10.6.4 and the latest Snow Leopard graphics update). I also use a USB-to-DVI adapter (one of these http://www.newertech.com/products/viddu2dvia.php). I use the 1.6b2 DisplayLink driver as recommended by the NewerTech site.

Before the SL Graphics Update, everything was fine.

After the SL Graphics Update I saw blue and white stripes on the laptop display if I did not have external displays connected. i.e. the laptop on its own, with no external screens (mini-DP or USB-DVI), would hang during boot. Connecting up one or both of my external displays allows the system to boot and everything works.

My workaround is to disable automatic graphics switching in the Energy Saver System Preferences. This tells me that the problem is a bad interaction between the DisplayLink driver and the on-board Intel graphics of these new MBPs with the new SL Graphics Update.

I hope this helps someone to reproduce the problem and that it will help DisplayLink to come up with a new version of their driver.

Regards,
Bill

Similar Issue
 

I am having a similar issue with a MBP i7. Happy to provide logs if needed.

Same problem on 2010 15in i7 MBP
 

I'm seeing similar but not identical behavior. The system has no problems booting. But without the USB display connected neither the LCD nor a directly connected display (via Mini-DisplayPort to DVI cable) will work. The LCD alone shows either snow or a random pattern. I can tell it is booted because I can make it go back to sleep by briefly pressing the power button and then pressing the right set of tab and space bar keys to select the "Sleep" option in the popup that normally comes up.

I'm using a Targus ACP51USZ USB-based "dock" connecting to my Macbook Pro.

I have tried both the 1.5 and 1.6b2 drivers.

Does disabling the automatic graphics switching help? If not you should uninstall the DisplayLink driver, disabling the automatic graphics switching, reboot and install the DisplayLink driver again.

Without a fix from Apple it will be hard to provide a better solution, I'm afraid.

I tried to summarize the status, cause, workarounds and fixes for this issue over here.