Hi David,
Since both the microphone and home button are not working, this would point me to believe that the charge dock connector came loose will the phone was being worked on. Microphone and home button both run through the charge dock flex. Open the phone back up and check to see if the connector directly above the battery connector is plugged in or not, try to reseat the connector. If it is plugged in correctly and is still not working, then it may need a new charge dock flex and/or a home button cable. Hope this helps.