Troubleshooting Guide: Unlit Digits your LED Price Sign
This guide outlines how to troubleshoot and resolve instances where one or more digits on an LED price sign are not lighting up even though the sign is powered on. In most cases, the first digit will be illuminated, while subsequent digits (e.g., second, third, or fourth) may remain dark. This typically indicates a break in the connection between the digits.
Each digit is connected to the next using a 16-pin flat ribbon cable, which carries both power and data. Use the steps below to isolate and resolve the issue.
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Tools Required
#2 Phillips screwdriver
3/32" Allen wrench (to remove the back plate)
Clean flat surface with protective padding
Replacement 16-pin ribbon cable (if necessary)
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Step-by-Step Instructions
1. Remove and Prepare the Sign
Carefully detach the sign from its mounting structure.
Lay the glass side down on a clean, flat surface, using protective material to avoid scratching or damaging the glass.
Use a 3/32" Allen wrench to remove all screws securing the back plate.
2. Access Internal Components
Slowly lift and flip over the back plate to reveal the internal components of the sign.
3. Identify the Faulty Connection
Locate the 16-pin flat ribbon cable that connects the digits.
Focus on the area where the digits stop lighting up.
Example: If the first digit is lit, but the second and third digits are off, inspect the connection between the first and second digits—it may be loose, improperly seated, or damaged.
4. Reseat the Cable Connections
Using a #2 Phillips screwdriver, remove each digit module one at a time.
Disconnect and reseat the ribbon cable between the affected digits, ensuring it is properly aligned and securely connected.
5. Power On and Test
Power the sign on and check if the unlit digits now illuminate.
If successful, power off the sign.
Carefully reinstall the components, flip the back plate back into place, and tighten all screws.
Reinstall the sign on the structure and reconnect power.
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If the Issue Persists
5a. Test with a Known Working Cable
Swap the existing ribbon cable with one from another working section of the sign.
If the digits light up, the original cable is faulty and should be replaced.
5b. Check the Digit or Port
If the digits still do not light up, the issue may be with the digit module itself or the port on the board.
Contact support to request a replacement digit module to complete the repair.