After repair Device HOT above dock connector plug/No service/No charge

Hi all

thanks a bunch for all your help over the years (I always come here first) Usually i find my answer straight away but i have a real brain teaser on my hands.

so Here goes. I got a I phone 4S in and it was really battered! the actual metal had split and phone was in a real mess.

i replaced the Middle Metal Bezel, Dock connector, Speaker, Jack, Wifi, Antenna, on off button and sound buttons, also the screen and back.

Now when i plugged it all back together it did not charge on the original Battery! so i replaced the battery with a new one it slowly ran down (while plugged in (while not plugged in it would drain about 3% a minute!!)) Once the battery was empty the phone would go into a Apple Logo Boot Loop.

This i determined was From the next problem! You see i Plugged the sim card back in and it said searching. Now this thing is on 5.1.1 so i didnt think it was the dreaded 5.6 update error (or whatever it was) I also thought it was not Software related because the Cover for chip (just above Where the dock connector ribbon plug is) is getting really really hot! At first i thought this was because it was Searchign Searching... all the time. But now iv Plugged the Logic board into my fully working Personal I phone 4S Casing and plugged it all up. and vice versa with my own logic board into the new casing to test.

My phone works connects up stays cool and is fine! But the One with the problem in my own case has now gone from searching to No Service. It still wont charge (well it did for 1% then started to drop again)

sorry for the massive post but im thinking iv reached my trouble shooting process now. I have checked all coils and resistors ect. on the board (Visually) and they are all present. (i have not checked under the Chip cover yet as im unsure how to remove this)

Any ideas? Any thing you would like my to test let me know if it will help!

Thanks again to all Who Read this Novella iv just written!

Chris