2002 Volvo S40 • 133,000 miles

Hello I have been having a problem with my gauges they all were not working my digital to but today my digital came back on but the milage is not moving, my clock is on the temp outside is on and the milage is on and my gas gauge is working but it's saying I only have a half tank when I know it's full does anyone know what it could be Please help me
June 6, 2012.

You may either have a bad connection behind the cluster or the cluster may be failing