Traditional incandescent string troubleshooting does not apply to LED strings. It can be frustrating and time consuming to locate a bad LED or socket without checking each one-by-one. One method to speed up the troubleshooting is to use a binary search reduction method. You will need a multimeter to perform this reduction test. Before proceeding be SURE TO UNPLUG THE LIGHTS FROM YOUR POWER SOURCE.
1) Find the segment break of the LED string (typically at 36th LED in a 70ct 120V string, but this is dependent on your LEDs, count and voltage) for the section that is unlit.
2) Remove the middle LED from the socket in the unlit segment (e.g. If the segment is 35 LEDs long, remove the 17th LED).
3) Remove the first LED in the unlit segment
4) Using your multimeter set to measure Ohms, place one probe in the first socket and the other in the middle socket. Look for resistance. If it is open, proceed. It it indicates resistance, one of the removed LEDs may be bad.
5) If the above test was open, continue to divide the string into halves for each segment, removing the middle LED and testing for resistance between the first socket and the newly removed LED socket, and the last socket and the newly removed LED socket.
6) Keep halving the section that has no resistance. You should be able to narrow down the bad LED or socket within a handful of testing attempts.
When testing your lighting, using your regular sequencing software is often not the best way to do it.
This allows you to send known E1.31 (streaming ACN) data to your hardware. At least then you'll know if it's a hardware or software problem you're having.