As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
MLI - FLT 3312 - EN ROUTE, MASTER CAUTION LIGHT BEGAN TO FLASH WITH NO ASSOCIATED ANNUNCIATOR LIGHT. THE AIRCRAFT RETURNED TO MSP. MAINTENANCE CYCLED THE POWER AND ALL CHECKS WERE GOOD. MAINTENANCE CHECKED SYSTEM CONNECTIONS AND COMPONENTS. ALL CHECKS SATISFACTORY. (X)