1999 Mercury Cougar Odometer?

My boyfriend has a 1999 Mercury Cougar, with 163K miles on it. Good car, runs great, but this morning I got into it, to run to the store & I noticed his Odometer/clock screens were blank. So I tried pushing the reset button and everything, but they were still blank. When we parked the car last night, they were working fine. They are still lighting up, but yet are blank. The mileage isn't there, or the clock. What's wrong? Could it just be a fuse? Or something serious?