Disclaimer: To get it out of the way before anyone tries to help me out, I did take apart my phone in order to replace my cracked screen/digitizer. I couldn't find any info on whether this voids verizon's support for my phone or not, but if so maybe someone else can still help me fix the issue myself.
Recently, as above, I took apart my phone, replaced the screen/digitizer with a new uncracked one, and put my phone back together - no issues there. When I booted my phone again, everything appeared to be working just fine, including sound, until someone called me. I couldn't hear them, but I later found out they could hear me. I could hear my ringtone and everything fine as well, but there's something up with my calls. Further investigation discovered that when I call someone, I can't hear the rings that you normally hear while waiting for someone to pick up - effectively, all sound is cut off from the speaker used on calls. However, if I place the call on speakerphone, I can hear everything perfectly (through the back speaker, that is).
Does anyone have any ideas as to what might be causing this, and how I can fix it?
Side note: I also noticed that my headphone jack appears to not be working properly either, as my phone simply keeps using the speaker when I plug them in and doesn't indicate it recognized anything at all. I'm not sure if this is related or not though.