Phone wont go into DFU mode
I have an iphone 3G, I can turn the phone off and on using the slider ,I can go into restore mode but for some reason I cannot go into DFU mode. Its not frozen or anything , I took it to a shop and they said the power button is not working.My question is" Will a bad power button still be able to turn the phone on and off? If it does how can this be repaired,do I have to replace the motherboard?