I have a Jandy RS4. The lcd does not display anything
It lights up but no words appear. I can run all devices from both the indoor and outdoor controls but I cannot set any programs. I tried replacing the lcd which changed nothing.
Pool & Spa - Jandy - AquaLink RS2/6 All Button Dual Equipment -
Answers & Comments
Verify contactor operational in outside box. if so check light transformer and lamps. Unlikely it is the Jandy if everything else works, but contactors do fail infrequently. Lights are a common failure.
This answer post was for inop lights, don't know why it landed here.
For dead display, sounds like the display driver chip on the display interface control has failed. You can try reseating the ribbon connector but sounds like you already tried that. Disassemble and unplug controller, look for heat affected parts or damage. Smell for burned insulation. See if you can borrow one from a neighbor and try. Regardless of findings, the chip is still likely bad and the board needs replacement.