The disconnected keyboard.
Yesterday night, when I was closing down my Dell desktop, Microsoft installed its Security Update for Defender. I had selected the option to install updates and restart. When the pre-desktop, picturesque screen presented itself upon restarting, I was unable to open the pin entry by hitting the escape key on my keyboard. I could, however, bring it to open by double-clicking with my mouse. Then, when I tried to enter my pin number, there was no response on the screen. My keyboard was no longer connected. I shut down for the night as I had decided to solve the problem this morning.
I had a new keyboard ready to go, in case the one I had was defective. I located the USB2 connects on the front of the computer and firmly reset them to be sure that they were not physically loose. I also patiently depressed every key on the keyboard to be sure that none of the keys were jammed. All keys were physically responding as would be expected. Booting up resulted in the same problem; mouse working Okay, keyboard not producing any results on the screen. But, interestingly, every time I depressed the escape button on the keyboard, the mouse cursor displayed the hourglass symbol for a few seconds which then reverted to the pointer cursor, without the pin box opening.
So, what was the problem with the keyboard? Was it:
A defective keyboard
A defective USB2 port
A faulty keyboard driver
Something in the computer's connections or wiring
Something in the programming of Windows 10
A glitch in the new update
Fortunately for me, I fixed it with my next guess. I disconnected both the mouse and the keyboard at their USB2 ports. I knew that the mouse was working Okay, so if the keyboard returned to functioning and I lost the mouse cursor, then it would be almost certain that the problem was with the USB2 port.
I had booted up to the point at which the pin could not be entered into the window for same. I pulled both USB2 plugs out of their ports and switched them over. Presto, the keyboard was back in action. But, interestingly, the mouse was still working also, even though a small window at the lower right of the screen proclaimed that Microsoft was installing the MOUSE (not the keyboard).
With the keyboard once again working, I can only assume that the keyboard driver was still installed. So, why was the keyboard not getting its signal through to the screen? Can anyone explain how this was the case?
Update 6-19-2020: I installed the Windows 10 2004 Update on my Dell desktop. It took a couple of hours to do so. All I had to do, after the installation did everything, including several preparation readings, downloads and restarts, was click for the grand finale "Restart". Then, wouldn't you know it, the keyboard was gone again. I pulled the switcheroo that restored the keyboard last time. But, this time around it didn't work.
I switched the keyboard and mouse USB2 cables to each other's USB2 port and I lost the mouse yet regained the keyboard. So, the diagnosis is that the leftmost USB2 port is having connection difficulties. The computer's top front has two USB3 and two USB2 ports. I have attached a four-port extender to one of the USB3 ports, and plugged the mouse into it. Now, once again, I am back in business with both keyboard and mouse, but still wondering what the problem is with the leftmost USB2 port. I will now check the Device Manager to see if the drivers are Okay.
No driver defect markings in the Device Manager, so I am guessing that it could be a physically worn out USB2 port. Perhaps not. Does anyone have any suggestions as to how to check the port or somehow restore its usability?
