phone was submerged in pool

John, drying out is not enough. you will have to disassemble your phone, and clean every part with 90%+ isopropyl alcohol. Use these guides to help you with that. Never forget the connectors on the board and the ribbon cables. Check for missing or burned components. Once it is properly cleaned, replace the battery and reassemble. Then re-evaluate for any further damage. Water damage is the most difficult to troubleshoot since virtually any part on the logic board may have failed.