Sounds like a critical system failure, when it is on can you check the console logs for kernel panics?

Have you attempted to hook up an external monitor to see if there is video out by chance?

A lot of times with the fans it could be your SMC or PRAM that needs to be reset. These parameters can sometimes go a bit wonky and cause all sorts of system issues, however I see that you have already attempted this. Where did you source the fan from? The laptop fans are typically controlled via software with readings from a thermal sensor, however if the fan does not have the exact wiring that the previous did, it will instead run full speed as there’s nothing controlling the voltage to it.

First problem, was you continued to use it after water was spilt on it. Any water spill should be treated seriously as the motherboard sits directly beneath the keyboard on most laptops, with a few exceptions having drainage ports that help to mitigate liquid damage. You could attempt to further dry it out by placing it in a dehydrator for a few hours on a lower temperature, but a lot of times if a liquid joins two or more circuits, there can be irreparable damage to the system. It’s not the answer you probably want to hear, but it’s a truthful answer. Your first step to potentially remedy it is to get it in a warm and dry area and let it sit to complete dry out. You can reattempt to start the device up after that point. The worst thing for a board is if it is a substance with salt or sugar, i.e. the coffee pills on laptops I’ve encountered too many times to count and the residue of sugar and dairy creamer left behind. Honestly, best of luck because it’s not always easy to return from water damage...

Try resetting the PRAM and SMC on boot. Here’s how to reset the PRAM: (1) Shut down your machine. Yes, all the way down, not sleep or logging out. (2) Press the power button and then press command-option-p-r. You have to make sure you get those keys pressed before the gray screen comes up or it won’t work. (3) Hold those keys down until your Mac reboots again and you here the startup chime. (4) Let go of the keys and let your Mac reboot normally. And here’s how to reset the SMC: (1) Turn off your machine (really, you knew this was coming at step one) (2) Keep the power adapter plugged in. (3) Press at the same time shift-option-control (on the left side of the machine) and the power button (4) Let go (5) Turn your machine back on with the power button. A lot of times these errors are caused by bad System Management Controller configuration, this is responsible for Power, Lights, Fans, and System Performance. Many times this can fix this issue.

Try increasing the volume on your phone first and then adjust on the headset. Many times these volumes are independent. If that’s not the case, how old is the headset?

Typically each connection is report to the operating system as functioning or not. The connection breaking off the logic board could prevent you from running the system all together as wiring it through another connection point is going to still fail to report that specific fan from being reports and would likely cause potential kernel errors and crashes due to the systems desire to protect the logic board components with proper ventilation.

Open it back up and check your cable connections again, chance are that a fan connection is loose, which will give you a blinking red light due to a the console protecting the board from lack of ventilation.

You could potentially have broken solder points where the battery terminals connect to power the phone itself. You could open up the phone, which are fairly easy to do as they are typically a single board with two screws holding the case closed and you can then pry the rest opening. Check the solder points on the battery terminals, it they are loose or missing you may be able to repair it by resoldering the points.

Not able to find a source, however you could Ebay to find As-Is or Parts-Only auctions and part out the pieces that function.