Water damage, not working, what to do?

After I bought this faulty but in very very good condition iphone, i opened i saw OMG it was totally wet inside and the water indicators were red.

I replaced LCD, battery, 30pin connector.

I submerged it for 2 hours in isopropyl alcohol and cleaned everything with a toothbrush....

Really i think i did everything to reanimate it, but after all of those moves the iphone is still dead!!!

When i plug it in it becomes hot but still stuck on back screen... even the computer doesn't detect it so it's not the LCD..

Do you have any other suggestions????? I think this is the most that i couldn't do, isn't it???