Hello Dave 2022
There are two things you want to check regarding connecting the MB074SP-1B to a SAS host. First, check the cabling between the unit and the card. Different cables should be tried to see if the issue is cable related. Next, check the settings on the card. MB074SP-1B supports single channel SAS. If possible, try directly connecting the SAS to the card to see if the drives are functional and try using a different SAS host.
Please let us know if any of these suggestions have any effect on the issue you have with our product.