could be a dirty or defective earphone jack. sometimes when you plug it in, it will mute your phone.
To turn off mute on a Samsung cell phone, locate the volume buttons on the side of the device. Press the volume up button until the phone exits mute mode and you hear the desired sound level. Alternatively, you can access the phone's settings and adjust the sound settings to disable mute.
unplug it
*6
You will have to put the phone on silent
Not possible - such a device would have to be physically connected to the handset in order to control internal functions such as ringer on/off or volume.
what is an unlocked cell phone
You will need another AT&T cell phone are a compatible GSM cell phone.
it may be because your phone is on mute and you have alot of missed calls.
You cannot I monitor another cell phone without targetting that cell phone to monitor the phone.
You cannot make a cell phone microscope. A cell phone is for talking and to text.
When you are on the home screen, use the small gray rocker switch on the left edge of the phone to change the ringer volume to mute (the scale goes from 0-7, 0 is mute, 7 is the loudest possible).