This sounds like your power button is sticking or stuck and this is causing the factory reset process to start. This could be due to moisture or debris getting around the button. A recommendation I found on an old reddit post is to try lightly prying around the power button to see if you can release it from its stuck position. You could also try using canned air to blow around the button as well.

Sounds like you will need a new L Button Key Ribbon Flex Cable, I have linked here a replacement listing on Amazon for reference. I have not replaced one myself so I do not have a recommendation on which brand to get.

They are M3 screws, the same screws as all 2.5" form factor hard drives.

There are several possible reasons for a flash drive to become corrupt with the primary reasons being age and removal during a write process. NAND flash, commonly referred to as flash storage, has a limited life span usually listed as Gigabytes/Terabytes written per year. USB flash drives do not usually list this figure, but basically the NAND flash gets worn out and has a higher chance of it having failures which will start being recognized by computers as corruption. If a flash drive is removed before it is finished writing all the data to the flash storage it can cause data corruption. Basically when you copy something to your flash drive and you get the copy progress bar, even if says 100% complete that does not mean that it is 100% copied onto the flash storage, it ends up sitting in the storage cache. If the flash drive is removed without ejecting it from the operating system anything in the cache will be lost but the flash drive is expecting a file to be there that isn't and so you get notified of a...

The HP EliteBook 840 G2 product range all uses the Intel I218-LM ethernet controller. From Intel's product documentation it outputs the link status speed via the following: (1) 10 MiB = Blinking Green (2) 100 MiB = Solid Green (3) 1000 MiB = Solid Yellow/Amber

It is unfortunate that this has happened to you. When cleaning out fans in a computer, especially a laptop, it is a good idea to make sure to remove all power (power cord and battery) and let the computer sit for at least 10 minutes to let all the capacitors drain down so that the chance of a short like this happening is almost zero. Without being able to inspect each component individually it is really difficult to narrow down exactly what is faulty from the short crated by the screw coming into contact with the two exposed pads. What I can tell from the pictures provided is that part of the systems VRM (Voltage Regulator Module) which controls and stabilizes the voltage provided to components on the motherboard, primarily the CPU, GPU, and RAM being the big ones. If a component in the VRM fails, in this case due to a short, then the voltage provided to one of those components may no longer be provided at the proper level and can cause instability or failure of the component that is being provided said...

I do not know the exact distance but the center of the coil is right behind the "G" logo on the back of the phone.

HP actually provides documentation for this on their support site in PDF form: available here. The keyboard assembly is part of the top case, not including the trackpad, so you will have to remove and completely disassemble the laptop to replace it. From the maintenance and service guide PDF, start at page 30 and follow each section through to page 60 which will guide you through the disassembly of the laptop and the final section give the replacement part numbers for the keyboard assembly.

It appears that they are not exactly the same. They use the same resistance potentiometer (10k ohm) but use s different type of pole (the part the joystick caps connect to) which would make the interchangeable joystick caps no longer compatible. As long as you are comfortable with desoldering and soldering in a new analog stick you can go with the ElecGear EL4 analog stick replacements available on Amazon.

This was an unfortunate issue that ended up being somewhat common on several models of MacBooks in the 2013-2015 year models. It is an issue with the display assembly, either in the LCD panel itself or the inverter board. Either way the fix is to replace the LCD assembly per the MacBook Pro 13" Retina Display Early 2015 Display Assembly Replacement guide. You could try replacing just the inverter board (the motherboard that is attached directly to the LCD panel but that will require desoldering the ribbon cables that connect the board to the LCD panel which is very difficult unless you know what you are doing and can solder surface mount components. Also sourcing the board appears difficult as I could not find one.