Omega B – X20XEV – Bj.95 – BC, range indicator spins

I changed the computer the other day with my station wagon because of pixel errors. Knows well. At the new (used) BC everything is ok. The only thing wrong is that it constantly shows the range between 600 and 700 km. I tried everything, pulled plugs and reconnected and even filled up fully. But did everything work out. Maybe someone have a solution for me? Thanks already in advance. Scoty 1