Hi Peter, Glad you posted where you are from as I am no longer interested in helping Americans. Is what it is.
"The LCD in controller went bad"...
Were you getting the same error message with the old topside?
A lot of IN.XE packs have issues with the low level power supply capacitor on the board. A repairable issue.
Remove the board from it's housing and check the capacitors for bulging tops.
https://www.poolspaforum.com/forum/index.php?/topic/53524-gecko-inxe-spa-pack-stuck-in-boot-up-low-voltage-power-supply/#comment-208142