Chosen Solution

I have a string of multi-functional LED lights (can be white,colored or cycle from white to colored) which have been in place for 7 days. A section of the string is dimmed. I checked each bulb with a bulb tester and all light brightly, This string is in the center of a 7 string run of lights and all the rest of the lights are brightly lit. How do I troubleshoot this issue?

Well when your LED lights dim it must be a problem with the voltage, did you checked this?