E7000 Flickering Display

Dell Latitude E7240/E7440 Flickering Displays
The following article describes some flickering display issues with the E7240 and E7440 laptops. Make sure these driver and bios updates are applied to your machine.
Issue descried at following: http://www.dell.com/support/Article/an/en/andhs1/636946/EN

Multiple external display issues when docked with a Latitude E7440 or E7240 portable system


This article provides information on "Multiple external display issues when docked with a Latitude E7440 or E7240 portable system".



Multiple external display issues when docked with a Latitude E7440/E7240 Dell system users have reported external display issues when docked related to the Latitude E7440 and E7240 portable systems. Symptoms may include:
  • External displays fail to detect during system power on while docked.
  • External displays may flicker.
  • Various screen resolution and graphic profile retention issues.
  • External displays may black out or go to power save mode after extended time.
  • No video on external displays prior to the loading of the operating system.



Solution options It has been determined that the following steps can be beneficial in resolving these issues:
  • Flash the Basic Input/Output System (BIOS) for the system to the latest revision to add initial display detection stability.
  • Download and Install the latest graphics drivers for the Latitude E7440/E7240
  • Download and install the Synaptics VMM2320 MST HUB Firmware from the Video section of the Latitude E7440/E7240 Drivers & Downloads.
    • PLEASE READ THE "Installation Instructions" from the Drivers & Downloads carefully prior to installing the firmware.
  • Disable DisplayPort 1.2 (DP1.2) Support from the external monitors menu as a workaround for monitors going black.
    • Not every monitor has the ability to disable or support this feature, please consult your monitors users guide for additional information.
  • No video on external displays prior to the loading of the operating system should only occur if using Secure Boot with Legacy Rom disabled (Windows 8 factory shipped units).
  • A workaround is to enable Legacy Rom for Windows 7 systems and to disable Secure Boot for Windows 8 systems.
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