LED Signs 101 – Technical Issues and Solutions

As we discussed in part two, we want to help dealers, sellers, owners, servicers and the industry as a whole have a better understanding of LED signs, regardless of brand or provider. Today, we’ll be discussing specific symptoms you may encounter with LED signs, and some general advice on how to isolate or fix the issues.

If you haven’t done so already, check out part one and part two of our LED Signs 101 series. 

Troubleshooting Specific Issues with LED Signs

We’ve listed issues below that can affect any LED display. While we can’t cover the details for every brand or provider we hope the information can help guide you in the right direction. And remember, if you have a Vantage LED display, we provide full support for the lifetime of the display, so please reach out to us and we can help you with specific issues asap!

Sign is Blank

  • Check your schedule. Is content scheduled to be playing? An expired schedule is the #1 common cause for a blank LED sign.
  • Verify your LED sign is powered. Check the breakers and make sure the correct voltage and breaker size is being used according to your sign specifications.
  • For a double sided sign, make sure to check both faces! If it’s working you may have a communication or power issue between the functioning face and the blank face.
  • Can you communicate to the display? If so, then you know the controller is working and you can check other parts of the system.
  • For displays using an internal PC Controller, try to log into the controller directly and verify the “player” application is running. If it’s an embedded system it may have diagnostic features that will allow you to see if it’s physically playing content.
  • If the display is still blank and you can get access inside the display make sure to check the Video (DVI) Board. Is it getting power? Is it getting signal from the controller and sending it to the other components? Check the Data Cables too.
  • The next item in the data chain is the Logic Board. Make sure it’s getting power and data. Unless you have a looped system, a bad Logic Board at the beginning of the data chain can cause the rest of the sign to go blank.

One or More Sections of a Face Blank

  • Verify power is supplied to the first blank section.
  • If you can get access inside the display, check the Hardware (DVI Board, Logic Board) that is responsible for the first blank section in the chain.
  • Check the power supplies in that same section.

One or more LED modules blank or “scrambled”

  • Always start at the first module in data chain that is not working. Remember, different brands run data in various directions. You can check by opening up multiple modules and seeing the order in which the data cables connect, or checking the labels on the LED module. Make sure it’s getting power on the power cable, and getting data from the previous data source (LED Module or Logic Board).
  • Check the module next to it that is working. Sometimes the output is bad, or the data cable between the two is bad. Swapping these boards can help isolate the issue.
  • If the module is getting data from the Logic Board, check the data ports and cable. You can take a working data cable from one port and temporarily swap it. This will help determine if it’s a port on the Logic Board, LED Module, or just a bad cable.

Line or Linear Errors Across the Entire Sign.

  • Double check the content. Make sure the lines aren’t in the media file itself.
  • Check the Logic Board. This is responsible for whole rows (or columns) of LED Modules.
  • Inspect the first LED Module in the series. On a smaller sign, it may be sending bad data to the rest of the row or column.

Errors and Display Issues with the Entire Sign

  • Double check the content. Make sure the lines aren’t in the media file itself.
  • Verify signal to the Video (DVI) Board. This board is responsible for the entire video signal to the rest of the sign. Make sure it’s getting good data from the controller, and good DC power from the power supply.
  • Check the controller’s video output. Sometimes a loose cable can cause video issues that will affect the entire sign.

Cannot Communicate or Send Messages

  • Verify the display is powered on, see previous sections.
  • Check the communications devices provided with your display are connected, plugged into the network, and are getting good signal strength.
    • Wireless Point to Point Antennas: These are typically paired to each other from the factory. One installed at the sign, the other at the building. Sometimes, the building antenna can get unplugged on accident, or simply needs to be powered off and on to reboot.
    • Hardline Network Communications: This is a standard network cable connection to your network. Make sure the cable is plugged in and getting a “link” light on your network equipment.
    • Fiber Optic Adapters: This is still a standard network connection but includes adapters on each end (sign and building) that convert network cable, to fiber optic. Make sure the adapters are working, and their status lights show connectivity according to any documentation that shipped with the units.
    • Cellular Modem: This is typically installed inside the sign, with an antenna installed outside the display. Make sure the antenna is mounted correctly and not being blocked from the standard cell tower signal. There is no connection to your network when a Cellular Modem is used, so most of the troubleshooting will be done at the sign itself.
  • Make sure your display has the correct IP address for your network. This is a common issue that can occur if you recently had network maintenance or a new ISP. You’ll want to contact your network admin, and your display provider support to verify the IP address is correct, or change it if required.

Keep it Up!

As your troubleshooting, remember to evaluate the basic flow of the system, then start to isolate the issue where the break in the flow might be occurring. Rule out items one at a time, and work backwards from the most common (or simple) potential causes, to the more uncommon (or complicated) ones.

We hope this information has been useful and helpful. If you’re new to LED signs, please remember that you’re not alone. LED signs are unique and exciting product that can appear complicated at first, but become less intimidating through better education, resources, and openness. We are happy to continue sharing and contributing to the effort, and encourage you to check back in with us regularly for more.

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