I just installed a new IPO. The receptionist had a CS70 on her old Spirit phone with an HL10 lifter. I installed the new 1416 with an APV-6A HIC cord to the CS70. The phone works great. The ring detect does not work. I installed the cord into the APV-6A and stuck it to the speaker but it does not send a ring to the headset. As in the instructions, compatibility is A, Speaking volume is B, listening volume is 2. I can't figure out what I am doing wrong.