Have a read through this thread as your symptoms are pretty much the same
Emphasis on checking your primary rails resistance relative to ground.
Also, can you take a picture of your modchip front and back so I can see specifically which one your using, also just just out of curiosity, can you also take a pic of your EMMC so I can see the part markings.
What your hearing in this area is likely just related to WIFI/BT just below which is normal. so not to worried about this.
Also, if you want, you can scrub that solder mask off and show me all joints which you soldered to (in future don’t use solder mask for jobs like this as it’s not needed 
) just so I can see general board condition.