Thanks man, I am checking those references you've been adding. I'll try them all and if no change, then try to get a spare.
It is now too late for any attempts to remove moisture, this is completely unnecessary.
I'm now convinced that the speaker is indeed faulty
I can't begin to guess what exactly is damaged. What you're seeing is some kind of side effect of one or more primary water damage.
I have some very good news, but before that, I just want to thank you for your time! I really appreciate it.
Firstly, I left some details out yesterday about how the Phone was dried after I dropped it into water. Firstly, I immediately switched it off and called that friend, he actually did not heat the boards, he used a brush and isopropyl alcohol to clean the board surfaces. And then he used the heating network but not heat, he just blew room temperature air to make sure that there were no droplets of water left after the IP had evaporated, everything was working like new then, nothing wrong.
I called the same guy again today and somehow he sounded like he already knew what it was. So I go to him, he pops the back open and using a micrometer, performs a continuity check on the contact points and the source. It turned out that one connection was weak. So the recommended fix was to get a new board but he checked the rest of it carefully and assured me that it was as good as new but just the fact that one connection was weak, possibly burnt out.
Anyway, the fix he performed was that he used a very thin insulated copper wire, the same one used in headphones and speaker windings and soldered one end to the contact point and the other one to the source. And Voila! it now sounds like nothing ever happened to it!!
I plan to get the board replaced from the service center soon though, no matter how small the problem is, I do not want to be running my device with a broken component.
Thanks again for your help, and one more thing, could you tell me how to close this discussion and mark it as solved!!