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Adaptive Display's Digital Signage Blog

Outdoor LED Sign Troubleshooting: Power Check

Posted by Chad Bogan on Fri, Jan 02, 2015

Troubleshooting a digital sign may initially seem quite overwhelming since there are tons of variables that impact how a system works.

You have to know that one of the leading causes of downtime is a power failure. When the LED sign is exhibiting strange or weird issues, there's a huge chance that it is a power problem.

Is the led sign getting enough power? That question should be the first thing you should ask.

Power issues create different symptoms that are challenging enough to be recognized in an instant. If there are digital sign issues that you cannot fix through normal troubleshooting methods, checking the power source is usually your best bet. 

It is always good to recognize common power failures that occur. If any of the situations occur below, the power supply should be verified immediately:


  • If the sign uses a generator for power
  • If the sign goes blank and there is no communication with it
  • If the sign is using portable power (like 208 VAC), particularly during special events
  • If the sign is not working after normal troubleshooting procedures
  • If the sign is on multiple circuits and some sections remain blank


System Voltage

Electrical devices and LED sign devices are configured to work on certain voltage ranges. Most devices work on 120 volts or 230 volts. Some devices can operate within a 10% range, but must remain within that tolerance. This is why you must not run an LED sign on 230 volts that is configured to work on 120 volts. Running a digital sign on a different voltage will cause major component damage and complete sign failure.

Voltage drop


  • Great distance of LED sign from the power source
  • Components work for a certain period, but fail repeatedly.
  • Sign or components drop at random intervals

Electricity travels through wires. Voltage decreases as the length of the wire increases. The voltage drop is about the gradual diminishing of voltage as electricity travels away from the power source. A voltage decrease causes lower power supplies for the sign and its components.

Wire Size


  • Lower voltage measured at the sign than the main power source
  • Semi melted or discolored wires/connectors
  • Small extension cords not suitable for commercial or heavy duty use

Wire size is vital in providing safe and adequate power to digital signage. A smaller wire size will cause damage to the sign and its electrical components. It will result in voltage drop and will the wire to melt and overheat. 

Loose Connections


  • Sign works in warm weather only
  • Sign flickers on and off or only work some of the time
  • Power is measured on the terminal side, but no power register on the sign

Loose connections occur when the thread that is stitched through the LED becomes too loose.

All electrical connections must be tightly pressed up for the electricity to flow through the circuit and for the signage to function in the right way. Loose connections tend to occur during initial installation or during system service work. This can lead to excessive heat.

Changes in temperature also affect electrical connections, causing the sign not to work in cold weather.

Main Power Source


  • Tripped breakers at the signage or at the building
  • The sign is completely blank on both sides without any communication

Power interruptions also occur from the main power source of the signage. This is caused either by the power panel in the building or the sign; or by a break in the line itself. 

Breaker Amperage

Breakers acts automatically by interrupting the electrical flow in a circuit in case of an overload or short. LED signage pulls a certain amount of amps, based on its configuration. It is important to use breaker size that is sufficient for this amperage. When the signage exceeds the breaker's amperage rating, the breakers will trip.


In those instances where you find yourself saying, "This doesn't make sense", then it's time to check the sign power. 









Tags: LED How To Guides