my samsung mobile GT-C5180 but when i make call then call has disconnected and when i switch off and on then may be work but after some time like 20 minute it's show same problem again and even i cannot received call. but this phone i am buy from hongkong and using now in hongkong with hongkong 3g sim card and if i used this phone in india with indian sim card then no any problem but if i used my hongkong 3g sim card with other handset then also no problem so please let me know if you have any solution of this problem ......Thanks in advance
It may be that the Phone is not designed to work with the carrier in Hong Kong, is there a different cell phone service that you can use there? If so, try that. Or borrow a friend's card and test it out and see if that works.