IPhone 5 issue, charging noise no power on?

I dropped my iPhone 5 in coffee, it came on, worked for about a week and then shut off, when I plugged it in it made a charging sound every five seconds, I replaced the mother board, LCD, and the charging dock station it's self, I then re assembled the phone, and it's doing the same thing, making the noise every 5 seconds, I then replaced the battery, and loud speaker and charger. Still no luck!

Water damage is very difficult to fix because it can damage the mother board which is the main part.
you must need it to bring directly to your nearest iphone mobile center or try to google it you will find the best service center for iphone.