Erratic Keyboard

I plugged in via usb a blue light teeth whitener tray to my Toshiba pc L75-B7270 (windows 8.1) for power. During use the computer performed with no problem. Just after I unplugged the usb device the keyboard started displaying incorrect characters from what I was typing. It did not occur to me when using it I should not have done this as the computer is 8 years old, hindsight 20-20 and all that. I was able to boot it in safe mode and the keyboard was still off, so I am thinking it is a hardware issue? The keyboard works w/wireless mouse & keyboard. I am not intuitive with computers and anything I try is based on what I read online. I tried to uninstall/reinstall keyboard driver via device manager but when I click on keyboard in that all that appears is properties and faded out-scan for hardware changes. Nothing happens when I click on either.

I don't know if there is anything else I can do, wondering if I ruined it beyond any repair that I can manage. Given it's 8 year old age I don't want to put in it the amount involved in taking it to a computer repair pro. If anybody has any recommendations, or based on this info, even can identify what the problem is since I am just guessing, I would appreciate it.

 

Shouldn't matter that it is 8 years old. It should not have affected your keyboard. Not sure if this is just coincidental bad time and the keyboard decided to fail at that point in time, or if there is something faulty in the teeth whitening tray. Either way, with W8.x, you can (if all is working properly) plug in and unplug USB devices when the computer is up and running. Actually, USB always has allowed this. The concern in the past was with data storage devices like external drives and flash drives where pulling the connector out before all the files were properly saved and closed might cause corruption. That should not be an issue with teeth whitening tray.

If me, I would use the whiting tray with a USB Wall adapter from now on.

For your notebook, you might try uninstalling the keyboard driver again, unplug all USB devices, shut down Windows and power off the notebook. Then remove the notebook battery for a minute or so.

Then you can power it up again and, with fingers crossed, hope it loads the driver and the keyboard works again. Otherwise, you are probably right and it would not be cost effective to have it repaired - unless you are willing to replace the keyboard yourself. As seen here, there are several YouTube tutorials showing how to do it.