nokia 6230 ringtone not ringing

i have nokia6230 handset.few days back its ringtone stopped working.i
checked thoroughly and find out that not only ringtone does not work when
some one call me but if i want to listen to ringtones myself even then it
doesnot give me sound of ringtones.
however when i connect my headset then i call listen to ringtones.i can send
and receive calls wothout any problem however using vibrator for alerting me
when there is a call.
i have checked the external speaker it is working fine when i put it in
another nokia 6230 handset.
can anybody tell me what could be the reason or faulty component in the
handset.
thanks
--
kind regards,
shahid bashir


--
kind regards,
shahid bashir
A589663
PhD student
CMCR
Electronic & Electrical Engineering
Loughborough University
Email : s.bashir@lboro.ac.uk
ext # 7114
Mobile : 0797931241