one
Replace two No. 7 batteries, and if the mouse recovers as before, it may be caused by damage to the primary battery or no power.
two
Power switch not turned on Logitech keyboard has a switch behind, to display the color is green to indicate that it is on.
three
Keyboard is locked press the white pair key, if there is no response, press the Fn Esc key to switch (different computers may be different)...
four
Driving problem
Download the SetPoint Mouse and Keyboard tool from Logitech's official website.