sanename

Thanks Jake, The solution in the post above also helped me with my E6420 with Nvidia. The HDMI and internal display now work.

I have the same issue as well. With docking station only VGA works, no video to external monitor on DVI. Any thoughts on what might be the issue.

Thanks.

With Optimus enabled, Nvidia is disabled and HD 3000 is enabled. All external display will not be possible, I believe it's linked to the Nvidia card. 

If you want to external display, you'll need to use the Nvidia card and have Optimus disabled.

Thanks for replying to the post, From reading the other threads I figured that in order to enable NVIDIA I will have to patch my DSDT and SSDT. Is that the only change that will be needed to enable NVIDIA and if so how can I do it? I tried enabling NVIDIA in clover boot option but did not help.

IF i disable optimus then the computer does not boot. Has anyone had success using the NVIDIA with E6420 & Yosemite? 

I was able to run Yosemite on my E6420 with Nvidia using optimus but the external monitor through dock is not working. ALso the camera was working but the image is distorted. Any pointers on how I can enable the external monitor? 

I have a E6420 with Core i7, NVidia and 4GB RAM, 320GB HDD