Found this out by accident, i got a second hand v3 off ebay and it worked fine. one day the earpiece stopped working, after my mate gave me his old broken (dropped in a pint) one to try and replace the speaker, as i was taking the phone apart i noticed the zif socket that connects the flec circuit (flex circuit from a pdf about fixing v3s) was open, i pooped the socket back down and low and behold the phone was back to normal... well i lost some of the little rubber screw covers but thats a small price to pay). On reflection i realised that i caused the problem when trying to clean the inside of the outer screen, i popped the cover up a little with some tweezers and must have caught the zif socket with them.