In some cases out of the 9 pins only 3 pins are required for the operation with DB9 pin 2,3 and 5 hence if thses 3 pins are present you can perform the operations however i am sure about it in ur connection. u can try out this option also.
I think u cannot interface 3110 directly to PC using DB9 because the four pins in 3110 are USB interface. U can interface it with PC using USB port. But If u still want to interface it with serial port of PC then u have to use USB to serial converter.
OR
Use any other mobile phone which has serial interface i.e. TX and RX. Normally the old models of sony ericsson have serial interface like T610, T630, J300, K500 etc.
I think u cannot interface 3110 directly to PC using DB9 because the four pins in 3110 are USB interface. U can interface it with PC using USB port. But If u still want to interface it with serial port of PC then u have to use USB to serial converter.
OR
Use any other mobile phone which has serial interface i.e. TX and RX. Normally the old models of sony ericsson have serial interface like T610, T630, J300, K500 etc.
u can use it. if there is a data cable with that model connect it to it.
if there is no data cable u can still achieve serial communication by using FBUS and MBUS protocol.
**broken link removed**
this tutorial is for nokia 3310
see pinouts for 3110 https://forum.gsmhosting.com/vbb/f139/nokia-system-connector-pinouts-455542/