Display has dark lines around the perimeter of the module causing a grid pattern on the display face

Potential Symptoms

  • Three or four rows of LEDs around the perimeter of the module look darker than the rest of the LEDs.
  • Black lines around each module.
    Dark lines module.jpgdirty module grid look.png
  • When the module is moved to another location, the dark pattern follows the module.
  • An outline showing around every individual mod on the display.
  • Darker edges of the modules.


  • Product Family: Message Displays
  • Product: AF-3500, AF-3550, Electronic Message Center (EMC) or Board (EMB), Marquee, Readerboard, Message Displays
  • Component:
  • Control System:


  • The theory behind why dust collects on the perimeter LEDs is that the display may have dirty, clogged filters. Ventilation may be pulling air through the modules instead of through the vents if filters are preventing good air flow. This may cause the LEDs to collect more dirt around the perimeter where air flows. Check for dirt/dust accumulation around the outer perimeter of individual modules.
    • Note: This issue could also be caused by loose louvers. Be sure to check the modules for loose louvers. If the louvers are loose please contact Daktronics at 1-800-325-8766.


Advise cleaning the display modules and replacing filters if needed. To Completely clean all the caked on dust off of the LEDs it may take a very thorough wash process or more than one display/module washing

  • Follow the steps and use the materials outline in ED-14158

KB ID: DD3456065

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