Chosen Solution
I’ll need to think about on what is causing your noise issue. If you leave the bottom cover off does that change things? What happens if you ramp up the fans using TG Pro did that change anything? Lets work on your second problem: Using a steel paper clip and a small magnet you should be able to locate the magnet in the lid using the paperclip (right side mid way along the side if I remember correctly). Now carefully fold the lid down so you can identify the placement within the case the sensor is located (don’t go to far). Now using the magnet you should be able to wink the display on & off as you pass it across. If you can’t you’ve identified your problem, Review Step 14 in this guide MacBook Pro 17" Unibody Logic Board Replacement making sure the IR (lid Hall sensor) cable is properly inserted. If the socket or cable is damaged that could also effect the sleep sensor. Update (01/17/2019) There are a few magnets here! The ones with the metal plates are to hold the lid down. The one we want to focus on is the one of the side and your image you posted shows the Hall sensor!
So it looks like you have a bad IR/Hall sensor cable Unibody MacBook Pro 17" Sleep light, IR & Sleep Sensor (10/11) This is the only source I know of that offers the cable alone. Otherwise you need a new upper case. Didn’t you state you replaced it? Maybe you should see about getting it swapped out under their warranty.
