Pantech Matrix Drops calls

I bought a Pantech Matrix from one end user to another, no transfer of warranty no insurance nothing. Now a week has passed by and my phone is doing two weird things.

1) My phone will only hold a call for about 8-9 minutes before the battery door warms up and the call ends. (it doesnt shut off; the battery doesnt die, it just drops the call)

2) Whenever i use the text messaging and review the massage with the five-way key the phone restarts. i lose my current message but nothing else.

These symptoms are problematic but not crippling, any advice as to a chip or cap being damaged that might effect it? i took it apart and examined the pcb boards to some extent but i did notice the water markers were pink (showing water damage to the phone)

Any help would be awesome.

Donnie