new 6408d+ phones hang

[rod1]

Hi,
We purchase a new sets of 6408d+ telephones a week ago and somethings weird happened the time we installed the phones.
We usually use the TTI feature to assigned ports to a new phone units but when we press the speaker phone to activate the unit, all I heard is a beep tone but not actually the dial tone. But when I use the handset, it worked fine and when I tried to busied out the port i just created, the spaker phone already worked. Why is this? Thanks.

 

[telcom1]

Are these phones 6408d+ or 6408+. Ensure that you have the phone type correct in the switch otherwise it won't recognize that you have a display or a two-way speaker.