having some trouble with my Q-pad mk-80, can anyone help?

[adambolt2000]

hello all, my q-pad mk-80 has recently gone weird. yesterday i had the keyboard plugged into my cherry G80-3700 and it was working totally fine, i then turned off the computer, un plugged the keyboard from the G80-3700 and plugged the keyboard in normally. to turn the back lighting on you need to hold "fn" and press "NUM8" a couple times. when i tried this today, nothing happened? yesterday i only had it plugged into my G80-3700 and i was only programming a few macros which were not even to the NUM8 key? can anyone help? (the keyboard is ps/2)