Answer to: iPhone stays in headphone modes after touch icFirst disconnect the charging port flex to see if problem get solved . If not then reflow the audio ic. You might have touched the audio ic while replacing it's neighbor touch ic.
Answer to: iPhone 6 - irregular backlight flickeringTry to change the brightness of the phone. If you dont see much variation then replacing back light coil should fix the problem. https://microsolderingparts.com/products...-coil-for-iphone-6-6s-6s-plus-iphone-se
Answer to: Phone will not get a signal after being removed from the blacklistCheck your ESN again that it's clean on www.swappa.com/esn