iPhone not working

[pomozki]

aaargh! my beloved (jailbroken) 4-month-old 3G packed up yesterday - anyone got any ideas before I take it in for repairs?
first, I noticed it was only vibrating, not ringing, when someone called
then last night, immediately after I made a call, the display vanished too.
now - people can call me but the phone rings (so quiet, it's inaudible) and I cannot take the call anyway because the display is not there and no matter what I press, nothing happens
it's fully charged by the way and can still be viewed by iPhone browser so no data lost so far
thanks :)

[Bitewound]

Restore it and see if it works properly - if not you're ready for the genius bar

[iNinja]

At least it should still be under warantee.....just!

[pomozki]

thanks but where to find out how to restore it and where the genius bar is? and I'm now in China - but bought it in NZ, even if I could find the receipt I don't the warranty works here? :(