Reply to this issue from Logitech Tech Support:
Thank you for contacting Logitech Technical Support. My name is Susan and I will be assisting you with Incident # xxxxxx-xxxxxx .
I understand that the keys on your keyboard are not responding except the F lock key and the battery indicator key. Please correct me if I misunderstood you.
It appears that your keyboard might be encrypted during first installation.
To try and resolve this issue, I would like you to try and decrypt your keyboard. You can refer to the steps below on how to do this:
1. Press Ctrl + Alt +F12 key on the keyboard.
2. Press the Connect button on the receiver.
3. Press the Connect button underneath the keyboard.
4. Press the ESC key on the keyboard.
Once you have performed the steps above, test the keyboard in simple text applications such as Notepad or MS words to verify if the problem persists.
Additionally, you can try the following steps should the steps above was unable to resolve this incident:
a. Press the Connect button on the receiver for 10 seconds.
b. Wait for 20 seconds and then press the Connect button on the receiver again. Press the Connect button on the mouse.
c. Insert fresh new batteries back into the keyboard.
d. Press the Connect button on the receiver.
e. Press the Connect button on the keyboard.
This would help to isolate the cause of the incident that you are experiencing.
If this does not address your question, please update this incident, describing the results after following my suggestions. Or, if you prefer, you can contact us directly by the phone numbers listed below.
Thank you for choosing Logitech.
Logitech Customer Supportwww.Logitech.com/support