CARRIER REEFER with LO MESSAGE IN SETPOINT AND ALARM 14

Hey guys
how are you
this is my first time in this forum

really i need fast response because i'm stuck

my problem is i had a problem with one carrier reefer container then i want to make sure that controller card is ok.
so i took a controller card from another reefer "which i have the problem right now".
then when i fixed back the controller card which i took to its original place in the reefer.
after switching on unit found that display is dim "no back light" also all led for "in range- sup- ret- cool-alarm- heat- defrost" are not working. and only on the display setpoint and supply temp numbers readings are shown.

also found that letters "LO" is flickering on the setpoint place on the display. and alarm AL 14 is active.

i checked power found that 451v is after the CB also on the "L1, L2, L3" for both PA & Pb contactors for the phase.

after following the manual found that may be current sensor is defective; i changed with new one but still the same problem.
also i checked all wirings found all in good order.

no i have problem in this reefer unit it's not working.
all i did that i took its controller card and put it in another reefer to check then after i put it back to its place this problem happened with me .

please i need help to save this reefer container unit