Water damage on iPhone 6s

Hello

I got this iphone 6s water damage with the original description of symptom:

• Power button not working no other test !

I would also add on description damaged screen and long time boot (see below) (boot with charging connector)

Water damage was located aound top speaker with very few/no corrosion but liquid indicator clearly red. A trace of liquid near the sim tray.

After using a know good screen and housing three troubles remained:

• long time boot : i mean time to get the apple logo and the backlight is about 15s, then time to get the springboard is quite short (3 to 5 seconds) : the apple logo appears after 15s and phone is awake in around 20.
• No touch ID, home button is working. I don’t have the absolute knowledge if it is the original home button but it was an original apple screen with apple touch ID and it was sealed by original adhesive so i would say propability is about 90% that it is the original button
• Rapide battery drain (about 3 h from 100% to 0%) with a known correct battery

All other functions of phone seem ok (camera, cellular, wifi, bluetooth, sound, mic, charge) etc.. but i ran very short test.

I have tested several lines after iso cleaning and microscope observation: didn’t find any suspicious caps.

It is my first ‘serious’ investigation and repair so I am a bit lost, here are my results:

• Bottom side of mother board is quite hot in stand-by position but no component is really ‘burning’
• As I thought that Touch ID fault could be linked to a power failure i have test : PP2.75 MANBA ok and PP1.8 Touch to manba ok also
• But i didn’t managed to have PP16V5_MESA_CONN or PP1V8_MESA_CONN on J4100 (but since i have the screen disconnected i am not sure that i should get these voltage.
• The voltage in diode measurement are quite similar to ZXW value
• I have notice one cap that was not colored exactally as other one and it was PP_GPU voltage. In diode measurement mode it is wery low (few millivolt) but since the iphone is booting and working quite normally i am not sure that is a short.
• on TP1120 I don’t have any tension when on : seems strange to me, I must miss something
• on TP1100 I have 0.5V

In term of battery current when power by a 4.2V injection the current during powered mode or stand by mode is very irregular 150ma to 300 ma in power mode and 50ma to 150 ma in stand by mode (I guess the battey drain comes from these high current even in standby mode)

And the altenance of high/low current is regular as if a power rail tries to raise and finally gets in safe mode and tries again..

No leakeage when iphone is completely off

I have several tools that let me make many tests, if you have idea I am opened to any suggestion.