Hello. Using the timer and swapped out two boards doing the same thing. After x amount of time, at least 4 hrs of CL time, the light on the LCD screen goes out. Timer continues to run, just very dim. Exact same system next to it does not do this. Swapped board and new board is acting the same way. Volt on both systems is steady at 23.9 v. Could it be inductance from ac? Same circuit for both boards but the left loses its light while the right side stays lit. Both are running OP 30 seconds CL 480 mins