Why is 123 not working?

Just to make sure, mine is a 3G phone. After ifixit suggested that there was a possible digitizer problem and after I had discussed the matter with my son, he took it to a shop he knows where the digitizer was replaced. It doesn't seem to be a big deal changing it - I got it back within hours - but my son won't tell he how much he paid to have it replaced. Everything is working fine now so I would suggest you take your Smartphone to a reputable repair shop or, if you want to, repair it yourself if you have the tools, which are screwdrivers, prying and suction tools, per ifixit. Good luck!