Q: cannot hear at  regular "ear piece"

Thanks for your reference.

I fixed the problem by inserting the "head phone" plug into the head phone jack and moved it in and out a few times. Apparently the phone was dropped (by the used and not known to me when I was asked to help fix the problem). My speculation is that probably the internal contact (spring loaded contact) was shaken and not making the good contact that allows it to work properly.