Answer to "Pixel 2 XL not fast charging after battery replacement"I had a similar problem and found the issue was with the replacement battery. under the black tape of the battery is a small PCB. The replacement one I had from a different vendor had a different PCB. I desoldered the PCB from the original and soldered on the new battery. So old PCB with a new battery cell and it regained the fast charge ability.
Answer to "Bottom speaker does not work after screen replacement."I had the same problem. I still had the components which was lucky and attempted to resolder them to the board. After many frustrating attempts I noticed that these are not transistors. They are small components the looked like inductors and contained only a few coils. I decided to simply short out connection with solder and this solved the problem. I will add that only one (the lower) of the two had become detached on mine.