回答“Can I swap the motherboards without loosing any data?”I understand your goal is to retain old motherboard into a new device. Yes. All information is contained on the chips on the motherboard. While icloud backup is highly recommended—because any mishap could destroy your motherboard circuit or cause memory erasure—if backup is impossible, swapping board (or more accurately, swapping everything except the board) should allow you to regain full phone function. (THEN immediately do a backup to prevent the situation in future.) Be sure exact same phone models. This trick may not work with newer models. We assume no liability if you brick your own phone in this process.
回答“Which Temperature on LCD Separators is free of risks?”For us Americans, that is Celsius. In Fahrenheit 80C=176F, and 100C=212F. The boiling point of water of course is 212F=100C, so a possible *home remedy* would be to stick your phone in a pan, sitting in another pan of water that is raised almost to boiling point. Of course using a thermometer would always be advised, but the pan floating on water would inevitably be just under 212F=100C. There is high risk of getting your phone wet.