Here's the repair guide to trace on Nokia X2 ON /OFF power key and END call key line paths.
If this line paths cut or open due to water damaged the device will not unable to power on.
On Nokia X2 there are two components that will be able to test
if problems occurs, which is the resistor valued 100ohms and a thermal resistor just mounted at the back of the PCB board, just behind near the END/Power key.
Do check and replace those two components if found faulty or damage. If this guide does not solve the problem, there is a possibility that the cut or open lies beneath to inner side of the PCB down to the power management IC.
Extra care and need more expertise to handle on major components such as the larger chips if working on it.