My iPhone 3G phone button no longer works. If I push it I get a black screen for a few seconds then back to the home screen. Everything else is ok. Any ideas how to fix this?

Question

The phone button on my iPhone 3G no longer works. Everything else on the iPhone works fine. I can receive incoming calls. I can make calls directly from Contacts. But if I press the phone button I get a blank white screen for a few seconds then it goes back to the home screen. I've tried the hard reset and also restoring orignall settings via iTunes but keep getting the same problem. Does anyone know how to fix this?
Thank you, Neil.

Answer 1

Thanks for the advice but I've tried resetting network settings and also the reset by pressing home and sleep buttons until getting the Apple logo. Still have the same problem. To be clear (because I mistakenly typed black instead of blank in the title to this thread): If I press the phone button I get a BLANK WHITE screen for a few seconds then it goes back to the home screen. I doubt it's the SIM card as I can receive calls and make them directly from contacts. What I can't do is view my favourite numbers or missed calls or access my voicemail, i.e. all the things you get to via pressing the phone button.