Audiovox PPC-6600 / PPC-6601 / XV6600 (HTC Harrier)

I setup and configured this device for my boss and he is not receiving new voice message notification. It work when I gave it to him but he must of accidentally turned it off, what does he need to do to turn it back on?

I did a search on assistance for his device and came up with this forum. Let me tell you guys you have saved me in the past few days. One on speaker phone on/off directions and the other on soft reset device. Keep up the good work.

Thanks in advance.