Continued...

Now, even with the res chipped off, the mobile, with battery connected, shows the SONY logo and then the blank screen after that (earlier, it used to show a charging battery) when I try to charge it using the supplied charger. So, now, I'm not able to switch on the phone at all using the power button but 'some' part of its electronics circuit appears to be intact as it shows SONY logo while charging it. It may be because that part of logic board is 'misbehaving' which takes input from power button or that the power button (mechanically) itself is not working as I don't hear the low tic-tic sound that usually comes when power or volume up-down or camera buttons are depressed, partially to fully.

Well, one thing that I learned from this episode is that one should not postpone the process of cleaning and then drying the electronics just after its exposure to any liquid.

P.S.: If anyone has any idea of what in the !&&* is happening with my phone, please reply.

I have a Sony Xperia U which worked fine before I stepped into ocean with it in my pocket. It got switched off on its own at that moment. When I at last opened it by myself after 2-3 days of its exposure to sea water, I regretted not cleaning (using isopropanol as I know now) and drying the logic board within hours of its exposure when I observed that some smd components and EMI shields caught rust by that time because of which one very small smd resistor, in the attempt to clean the rust surrounding it that it caught, got chipped off. After that, I used hair blower in hot mode to dry off the board for long hours. After this much,the mobile stopped charging,for a while,using supplied charger(so I bought a cheap 'battery' charger to indirectly charge the battery).Interestingly,the mobile used to switch on(even with the res chipped off!)but yes,it used to take touch input intermittently even when I didn't provided any. power button acted as if pressed even when I didn't press it. Now its not switching on at all