Having problem with registering the Portable Station KX-TD7680 with the Receiver KX-T0141.

Receiver programming complete on the KX-TD50A, etc. PBX acknowledges KX-T0141 fine!
Have tried Function] *[(to search for receiver. (only 1 Receiver ) Have tried Menu SYSTEM SET *2 (Registration) This is second PS tried. BAD out of Box Units?