I am new to NEC products and I have a DTerm phone with an attached lamp field being used by the receptionist in a remote office with a 2000IVS. Two days ago, the msg wtg lights for both the receptionist's personal vm and the general mailbox wouldn't go out so we told her to use code 793 to turn off the lights. It worked like a charm but now the msg wtg lights won't turn on when there are messages. Please help.