Ford Ka CD Player problem?

I drive a Ford Ka....it's a EX51 reg.

The fuse box needed changing and since then the CD player has been flashing for a code. I tried random numbers and then all of a sudden a countdown started! I turned off the power and switched it back on and the countdown continued. I don't know what to do! If the countdown ends does the CD player start again....it was counting down from 30 mins, it's now at 25 mins....but I turned it off through fear of the unknown!