...SOLUTION: Power down the system. Verify that the controller is fully seated. Then power the system on and look for helpful error messages displayed by the controller. If this doesn't help, contact your HP service provider.
Description: ADU requested the identify controller data from the controller, but was unable to obtain it. This usually indicates that the controller is not seated properly or has failed.
Action:
If this does not solve the problem, contact an HP authorized service provider.