Hey,
I love this phone, I've had mine for years now, those soft keys on the front of the phone are actually controlled by the charge port. If you plan on replacing it yourself there are a few things to keep in mind.
Order more than 3. Yes, the failure rate on these parts is SO BAD that ordering less would only leave you frustrated. The charge port module on this phone controls the three softkeys, the charge port..(obviously) the antenna, and the main mic.
ALSO- take care removing the coaxial cable that runs down the right side of the device (when the phone is on it's face) if it gets damaged in the least, you will have abysmal signal, and you might be able to make a phone call standing on top of a cell tower... MIGHT.
Your problem is an easy one though! Don't worry, and don't go about doing anything software related, as 9/10 this probably isn't your issue.
-Samantha Stout.
Device Saver since 2013, fixer since 2002.