There seems to be a problem with the Dell E6420 when it isdocked and the video output is to DVI cables. I don’t believe VGA output isaffected by the problem, based on the information I’ve collected so far.However, we have seen the issue occur globally and can expect to see morecases.
The only solution that seems to work is to disable theOptimus video setting in the Dell BIOS. The Windows video driver may need to be updated or reinstalled to correct some issues caused by disabling Optimus inthe BIOS. Hopefully Dell can provide a BIOS update to correct the problem because it will impact the performance and/or battery life.
Just to confirm, we had a couple laptops here at the operations center that has this same issue. Updating the BIOS does not work unforunately. Disabling Optimus in BIOS does work though. The PBA screen does appear correctly when that feature is disabled.