How do I fix Berlinetta Speedometer, 1984 5 Litre

Hi gang, I have a problem...since I had body work done on my 1984 Berlinetta, the digital speedometer does not work, nor does the odometer. When I start the car, the digital dash lights up, but shows NO mph, and the odometer hasn't moved since 75 000. Do I have to remove the interior dash board to look around?