No imei, blank baseband iPhone 5 water damage.

I have a problem with a iphone 5 that had water damage.

The iPhone worked fine no problem at all. The only problem it had was making calls. When you made a call you couldnt hear the person or the person couldnt hear you. audio IC problem i think.

So i have opened the shield cleaned the logicboard with isopropanol. After that i made a call and it worked.

So i closed the iphone but after that the problem came back.

Cleaned the logicboard again and put the phone together, i wanted to test the phone, but phone stopped reading sim. I noticed that imei was gone and baseband was blank.

Did some research and could be the U601_RF baseband power supply failure.

I marked where there was corrosion

also a resistor of conductor is been missing from the logicboard.

what kind of component is the missing one ?

With the missing component the sim has been read, and also the live call were successfull.

I want to know how i can troubleshoot which component i need to fix these problems. I have micro soldering experience and the right tools to do this repair.