Good News Brian, is that the fuse can indeed be replaced, but ill tell you what...its not the easiest repair, if you're not confident with you soldering skills you could quite possibly easily come out with more issues that you began with. Ive been successful a few times for clients in the past but with the combined issue of the water damage you would be taking a huge risk. You could also try cleaning the area with 99% Isopropyl Alcohol to eliminate the water damage factor. (Be sure to allow PLENTY of dry time before powering the MacBook on again) or You could look into replacing the entire Logic Board, but thats also a very expensive route, (although without the risk of course).
Certainly it can be fixed by replacing the LCD and digitizer. It sounds like they were also bent during the accident and these screens are very fragile. even the slightest bent can crack or damage the LCD. The blue you see is the ink being illuminated by the backlight
Sounds to me like your internal ear speaker has gone bad. When switching to speaker the phone uses a different output speaker, you may want to check and see if your phone is still in warranty. Also, you can try taking a small brush and cleaning around your earpiece speaker. In some cases dust and other debris can collect and muffle the speaker, and considering how tiny these speakers and their speaker grills are it doesn'take much dust or debris to make it hard to hear. But i'd bet on the internal speaker needing to be replaced. Update (08/05/2017): The speakerphone on most if not all phones are located at the bottom or the on the back (add-on to previous comment) hope this helps
yaheyaarakil you are correct. The memory cannot be removed from the Nexus 5 it is not made to support a standard micro sd card, instead the memory is stored via the internal RAM. However to answer your motherboard inquiry, it CAN be replaced. You can access easily by carefully prying off the back cover held by plastic clips and removing the battery and mid frame along with the interfering components. iFixit already logged the teardown for your use : Desmontaje del Nexus 5 And the part can be purchased online for about 80 bucks, plus shipping of course. Id recommend searching eBay first before venturing toward other avenues.
Ive heard that the compass calibration fix has worked for some but not all, as Kenny stated it is a fairly common issue with the iPhone 6 and also the 6 Plus as well. I recommend a simple soft reset to correct the error. Simply hold down both the power button and home button for about 8-10 seconds until the device powers down, and then turn it back on using the power button and the issue should be resolved. It seems Apple has dropped the ball with the most recent updates to iOS 9. I hope they evaluate and calibrate some changes sooner than later.
Check the connections from the lcd to the logic board for error, one slight misplace on either the backlight or LCD connector can cause display issues. In the event the connectors are perfectly set and there are no signs of debris or interference, soft reset the device. If after these few steps you are still experiencing issues, you may have a defective LCD.
Here are a few possible causes : -The ink cartridges are empty -The ink cartridges are improperly inserted -The motor connecting to the ink tray is defective refer here : Epson Stylus NX230 Troubleshooting