Not enough character space for WiFi access on UN55MU6490

[JD251]

I can't enter enough characters for my router password to connect to WiFi. I am short by two characters before it just tries to connect. 

[ladysnoopy]

I am not sure of my model but it is a 3 yr old never used till i got it, and mine is the same .  I get to the 6th character entered and then it switches over to tv picture and it obviously is not then connected.