Samsung SGH-D606 - Manual (Page 153)

Solving Problems
147
The audio quality of the call is poor
♦
Check the signal strength indicator on the display ( ); the
number of bars indicates the signal strength from strong ( ) to
weak ( ).
♦
Try moving the phone slightly or move closer to a window if you
are in a building.
No number is dialed when you recall an Contact list
entry
♦
Check that the number has been stored correctly, by using the
Contact list Search feature.
♦
Re-store the number, if necessary.
If the above guidelines do not help you to solve the problem,
take note of:
♦
the model and serial numbers of your phone
♦
your warranty details
♦
a clear description of the problem
Then contact your local dealer or Samsung after-sales service.