Hi @mattb38390
With a water damaged phone ''***do not try to charge or to turn it on*** and then ***remove the battery as soon as possible*** ''to minimize any further damage.
''The impurities in the water causes corrosion and provides circuit paths for the electricity which were not in the phone's operating design and could damage the components. The corrosion starts immediately and is ongoing until it is completely cleaned away''
You need to dis-assemble the rest of the phone and clean ''all the affected parts'' using ***Isopropyl Alcohol 99%+*** (available at electronics parts stores) to remove all traces of corrosion and water. If possible do not use "rubbing alcohol" as in some cases this is only 70% IPA or less, can contain additives which may leave conductive residues and is not as effective. If you do have to use it check the label to verify the amount of IPA. The higher the percentage of IPA the better
Here is a links that describes what happens.[[Electronics Water Damage]]
As always with electronics, especially surface mounted pcb be gentle when handling and especially when brushing away the corrosion. You do not want to remove any components from the board. Remove the shields that may be covering some components as the water may have got in under there. The ends of any flex cables and their connectors need to be cleaned as well
Hopefully after you have done all this the phone ''might'' possibly work correctly again but given that the systemboard has been dropped then most probably not.
Here is the [document|42037]|troubleshooting guide] that may help.
Start on p.14 (of 53 pdf) ''Sect. 8-4-1. Power on'' and follow the flowchart and see how far you get. Given that it did vibrate before without a display it seems that you may have to replace the screen first and then continue further. Search online for ''GH96-13053A'' to find LCD suppliers that suit you best.
Use the search function of your browser (Ctrl + f ?) to find the location of the components mentioned in the flowchart on the board layout diagrams in the guide. You will have to zoom in a lot 400% - 500% to see them