My Sharp GX25 cannot be started!! Pls help me

[imranz]

I am from Malaysia but i have Sharp GX25 as a present from my sister in UK. I dont have problem to enter my sim card to the phone at first. But when I upgrade my simcard to 3G, the phone started to restart. When the phone is searching the network, it's going to restart. After a few times restarted, the phone could not be 'on' anymore. When I switch it on, only white screen I saw with the light on the screen was On. I cannot even switch it off again until i release the battery. If not, it will switch the light on but the system was hang at that point only. I couldnt even see the Vodafone logo as before when i started the phone. May I know, what is the problem actually? Is it the software corrupted or the phone's IC was damaged? Somebody pls help me... I have the usb data but i cannot find the right software to solve this problem in the internet. I really need help.....pls...Somebody pls help me...