[Galaxy Note 4 Q&A, Help & Troubleshooting] @rbiter:
That is if you're not scared to take out sixteen screws and figure out to take the back plastic fame off. I havent found a definitive guide for fixing gps and reading quite a few posts of pinch this area or twist/torque your phone and not working I decided to take the phone apart. I did find video guides for screen replacement that I used to figure out this adventure. Heat gun is not needed, but recommended. I highly recommend the plastic spudgers you can get from places like ifixit, but all I had was plastic butter knife and my computer repair kit, of which you will definitely need a #00 Philips screwdrivers.

Ok. The first picture is what you want. How I got to that point was I took out all 16 screws. If you have a heat gun, heat the edges of screen from front first. But if that is too much trouble or scared you'll burn your screen then you're going to have wing it like I did. Start separating the plastic inside the battery cavity. Be careful not to break the little strip of plastic around the micro SD card like I did. But try and make sure you have gap between the phone and insides of the battery cavity. If you have heated your screen adhesive up this will be less tricky. Push out on the micro SD card slot and upper right area of battery cavity. There are plastic locking tabs around the back plastic frame that lock into mid metal frame. Don't be scared to push but also take caution of your screen as our amoled's are very fragile. Keep pushing. Separate the inside parts again if you have to. You're trying to open enough one side will pop out enough you can get a spudger or in my case a plastic butter knife under one side screen and separate the adhesive and give you better chance of pushing out the phone away from the plastic back. Take care when pushing your knife or spudger underneath screen. Only go in about .25"/.5cm max. Don't want to scratch or mess up screen or connectors. In my picture it kind of looks hinged but is because there is adhesive on the other side keeping it like that. But keep pushing til it happens. Once it does separate the rest is easy.

In the second picture you'll notice 3 parts of plastic that look like they can be separated from the back plastic frame. Don't pay attention to that part. Pay attention to the contacts underneath those 3 places where it is like your antenna contacts are on the pcbs underneath. Some other references said the contacts above the vibrator motor were the gps contacts. Well I bent those up and snapped phone back together and tried gps. Didn't work. Btw, you should probably use something plastic or non conductive to bend the contacts up. My plastic butter knife was too thick so I used a very very small flat blade and was particularly careful. I bent every contact related to those 3 pieces of plastic I pointed out on the back plastic. I snapped back together and tested again. Satellites galore. Locked 6 satswithin 15 seconds and locked to another couple next 15 seconds down to 30 feet, inside my apartment. Turned gps off and went outside turned back on and was locking almost 15 satellites in less than 15 seconds to less than 10 feet accuracy. A few more seconds and I picked up more satellites.

Anyways, you can finish there or do some maintenance inside your phone. On all the places those metal contacts contacted on inside of the back plastic frame I used a qtip with cotton torn off and a drop of arctic clean #2 to clean the black spots I saw on contacts on inside of plastic frame popped off. I also cleaned all the contacts. Pushed down on any connector I saw. Used another qtip to clean around the USB cavity on the back plastic frame. Used another qtip with cotton torn off to clean inside USB port. I pushed on the top PCB where underneath are your display related connectors. One thing I forgot was to clean camera since it was exposed but luckily no dust or fingerprints got in it so my camera is fine. While you have it open figure out anything else to routine. Look at the USB PCB closely and take pictures if your USB port I'd flaking out on you for future reference. When done snap back together.

As an aside, when I got to the point I was ready to fully put back together, I notice my power button was mushy when I tried powering on to test before i put all screws in. Took it apart again and kind of slipped. Scared me, and I had reason to because when I put frames back together and made sure power and volume buttons weren't mushy. My screen didn't come on but it vibrated like it was on. Took apart again and pushed on the top PCB and heard a resounding click. Snapped back together turned and screen was good. Whew. Then I put EVERYTHING back together. 16 screws back in. Double checked all the tightnesses by hand and try not to strip any. I'm sure that will be a bad headache if you strip a screw.

After that, *#0*# and do every test to make sure all hardware is good. Goto developer options and Test your pointer location and touches. Test your repaired gps.

Sorry I didn't have better pictures. The moto x is decent camera but didn't take all the pictures I needed because I winged it with common sense and some of the pictures didn't come out well that would helped a little. If you follow all the directions, are careful and pay attention to detail that I might've not pointed out your gps and cellular reception should all have improved if you wiped the contacts clean and bent up a hair. Should've got rid of oxidation, dirt And improved contact so reception should improve a couple dB and your SNR on gps should be quite good.