press and hold the # key for about 4 seconds
it will say do you wish to change line
yes
you are now back on line 1
your phone is in ALS mode and is connected to line 2 but I guess your sim card does not have 2 lines
so you need to be in Line 1 mode
It will recieve calls in Line 2 on line 1
as it "listens" to both line 1 and 2
but only dials OUT on the line selected
or the long route to it is menu call setting change active line
Nokia user / modder since Nokia Orange and Mobira user too before that