Why the left ctrl buttom stop working?

I suppose that by Lcrtl is Left Control key.
Left Or Right CTRL and C are editing key sequences. They copy a previously selected text or object and put it in the clipboard. Then if you press Left Or Right CTRL and V sequence, the content of the clipboard is pasted in the text your are editing at the location of the cursor. However if you select nothing to copy, or you do not Paste what was copied, you won't see anything happening.
To summarize: You will see the effect of CTRL and C only if you press CTRL and V.
Left OR Right SHIFT = is supposed to type the plus (+) sign.

Reinstall the OS and don't update the drivers? it may be a newer driver for the keyboard that isn't working.

For this model specifically, the following will get you into service mode.
Hit "Clear / Stop" Buttom then "107" then hold down "color print" buttom for some sec then you are in service mode
If that doesn't work, you can also use Clear/Stop,1,0,7, Clear/Start.
Each key should be pressed and held until you hear a beep

Try this link:

https://community.logitech.com/s/feed/0D53100005JmgiMCAR

Try Ctrl+F2. It should work..

The buttons are not working due to the fact the "Brain" has detected a fault condition, most likely the Power Supply and or magnetron, or High Power Diode, has "Faulted" and it shuts down for Safety reasons. Due to the danger existing inside MW, I recommend that you have it serviced by a qualified person. Always get a firm "Quote" before proceeding with any work. Be careful, as often a repair may cost as much as a new one.

The Ctrl-alt direction key sequence is supposed to be used for changing your workspace. On my computer at work it changes the screen orientation Ctrl-Alt-Up - right side up
Ctrl-Alt-Right - 90 degrees
Ctrl-Alt-Down - 180 degrees
Ctrl-Alt-Left - 270 degrees
(If that doesn’t work, try Ctrl-Shift-R)

When one key stops working in a Keyboard there is dirt or some other obstruction between the contact layers and the board needs to be dismantled and cleaned or the contact layer has been broken and the keyboard will not respond to that key any more. The first is more likely unless the board has been really abused.

1. If you right click on the desktop and look at graphics properties, or something similar to that, then you should get a menu for your display adapter control panel. Usually the screen rotation is right there. Sometimes it's as easy as a CTRL + arrow key combination, but I'd rather see you adjust it from a menu.

2. Ctrl-Alt-Up - right side up
Ctrl-Alt-Right - 90 degrees
Ctrl-Alt-Down - 180 degrees
Ctrl-Alt-Left - 270 degrees (If that doesn’t work, try Ctrl-Shift-R)

3. If you have the intel video chipset, I believe pressing CTRL+ALT+ one of the arrow keys should fix your problem.

I think it was ctrl+alt+right, but if that doesn't work, try the other three arrow keys.

However, if that doesn't work (especially if you do not have intel video), then right click on your desktop, go to properties, and go to the advanced tab. There you should find some setting that will allow you to reverse the rotation.

I have the same problem with Microsoft in both wireless and plug-in.

platypus