All or some of the function keys do not respond
Possible causes:
1. Keypad connecting
plug has been not
fit-in properly.
2. Keypad is damaged.
3. Upper board is
damaged.
Fix:
1. Remove the console cover, and then check if
keypad cable is connected properly to the upper
board.
If it has not been connected well, reconnect it
to the terminal and check again.
.
2. Keypad or upper board is damaged.
Replace the console