SAN can detect only one COntroller as read

in our NEC SAN there are two controller with cache memory and service processor
in second controller service processor showing as faulty
we power off the SAN ,remove this controller and reinsert it
when we power on the SAN the two service processor showing as faulty in two controller and two PS changed it's status from ready to faulty and from faulty to ready every 5 second
we power on one server and the server can detect the LUN and read /write on it
we remove second controller and power SAN
first controller showing as ready
we replaced second controller with new one while SAN is off
new controller showing as ready but the first controller service processor status be faulty and one of two PS changed it's status from ready to faulty and from faulty to ready every 5 second
Host Director and cache memory in two controller are ready