Either the motherboard or the LCD is going out .

More than likely the screen was incorrectly replaced . Without looking inside almost impossible to tell the cause , but it’s probably your LCD connection incorrectly put on

Actually scratch that . If you’ve just replaced the HDD with a new one your computer basically doesn’t have a primary OS to boot from . You will more than likely have to install a fresh OS on to your new HDD then try again . If that fails don’t worry like all state stands … your in good hands ! Lol Update (03/09/2020): Yea after rereading im almost 98% certain that the computer is doing that because it cannot find a HDD with a fresh OS to reinstall to your Mac . Disk utility , partition drive !? Open Finder from your dock. Select Applications. Scroll down and open the Utilities folder. Double-click to open Disk Utility. Select your hard drive in the Disk Utility window. It will be the first drive on the list. It might be named "Fusion," or "Macintosh HD." Click on the Partition tab. You will be prompted to either add an APFS volume or a Partition. Click Partition. Click the Add partition button it looks like a plus (+) symbol. Change the size of the partition you wish to use by dragging the resize...

To be honest I believe it has to due with the age of the version of Windows your using altogether. Have you tried installing windows 10 from a fresh boot img? Update (03/09/2020): Or maybe your default boot img was somehow changed . If your computer is set to first attempt to boot to another device, this may cause issues with successfully booting to Windows. To reset your computer's BIOS to factory defaults, perform the following steps: (1) Restart the computer. # during restart, tap the F2 key repeatedly until you see Entering Setup in the top-right corner of the screen. (1) Depending on the BIOS, you may need to press a key that is listed at the bottom of the screen to load default settings. For example, F9 on the Inspiron N5110. (2) Press ESC to exit the BIOS, and be sure to select Save and Exit to save your changes.

Have you tried to hold command+alt+R ?

Wipe down the charging contacts on the Home Base and on Roomba with a clean, lightly dampened melamine foam such as. Press and hold the CLEAN button for 3 seconds to clear your previous cleaning job. Verify Roombacan return to its Home Base by manually facing Roomba, within 6 ft (1.8 m), toward the Home Base.

Unfortunately chances are high that you have damaged your phone due to water . Ip6 and 7 aren’t really explained too good , they claim to be able to be submerged under water but truth is it’s barley water resistant:(

If it’s only the left half, I’m sorry my friend your computer has suffered a stroke ! Na lol seriously if it’s a few keys not working 7/10 times i would say the culprit is water damage . Try popping off the plastic and just pushing the rubber part of the key with your finger and update me .