CS1000 spead dial button lit up

[M Wong]

Hi there
I recently received a request to take a look at a 2616 phone and noticed that the speed dial button is constantly lit up. I've tried unplugging the phone, swapping to another 2616 and yet the button still lights up.
Can anyone suggest any input as what is causing this? I'm still quite new to all this system.

Thanks

 

[KCFLHRC]

Print the phone out, maybe the key is mislabeled??