Knowledge Base

This article provides information on issues regarding flickering video along with troubleshooting steps and driver links to resolve the issue.

Flickering / Blinking Video on External Monitors

Dell Latitude E5250 / E5450 / E5550 / E7250 / E7450 may encouter video flickering / blinking when connecting to a docking station attached to dual external monitors. The video will blink intermittently for about 2-3 seconds at a time throughout the day when connected to the DisplayPort (DP), Digital Video Interface (DVI), or Video Graphics Array (VGA) cable connections.

Docking station part numbers reported with the issue.

• CPGHK - E-Port Docking Station
• 8RNJ7 - Older E-Port Docking Station
• 35RXK - E-Port Plus
• JKJ9X - E-Port Plus II

Recommended Troubleshooting Steps

1. Reseat video cables to docking station.
2. Check refresh rate and resolution of monitors - for instruction please view our article Adjust the Screen Resolution, Color Depth, Refresh Rate and Size of Fonts and Icons
3. Ensure the BIOS is up to date by visiting the Dell Drivers & Downloads page.
4. Also, update to the latest Video Driver by visiting the Dell Drivers & Downloads page.
5. Update to the latest MST HUB Firmware by visiting the Dell Drivers & Downloads page.
   Note: The MST HUB Firmware may be listed under the Video category in Drivers & Downloads page. For more information, refer to the Dell knowledge-base article How to find the MST hub firmware when not listed on the support page.
   Note: In order to flash the MST HUB, the latest video driver needs to be installed and the system must be docked with an active external monitor connected.

Should these steps not fully resolve the issue, please contact Dell Technical Support.