Often, as SCXI chassis get older, they exhibit odd functionality changes when the backplane becomes more electrically worn. If you have isolated the issue down to a specific card or the chassis, you will likely need to either replace the chassis or send it in for repairs. If this is the case, it may be a good time to consider upgrading from an SCXI system to a PXI system, as SCXI repairs are often expensive. Contact NI Sales
if you would like to discuss this option.