Microphone and Home Button don't work (1st Gen. iPhone)

My iPhone (1st Generation) was dropped yesterday. Everything is fine except the home button and microphone no longer work. Reseting the phone doesn't resolve the issue. The speaker does play sound, but the only way people hear me on calls is if I use a plugged in earpiece with a mic (or a bluetooth).

I don't see in your guides how to get to the wiring underneath the home button. Is there a loose connection I can check, or would I need to replace the whole unit? (same applies to the microphone)

Thanks!