As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
GPS L & R INVALID AND MESSAGE FOLLOWED BY GPS & IRS LIGHT. IRS LIGHT WENT OUT UPON MASTER CAUTION RECALL. GROUNDED-YES. DIVERSION TIME 52 MINUTES-L & R SIGNAL VALID ON GROUND. ALL FAULTS RESTORED. PER CREW BRIEF BOTH GPS SIGNALS WERE INVALID FOR ABOUT AN HOUR NFLIGHT. FMC'S AND GPWS LOGGED L & R GPS FAULTS LEG 1. REMOVED AND REPLACED BOTH L & R MMR'S, REF B737-900 AMM 34-31-42, OPERATIONS CHECK NORMAL. ALL LLM TEST PASSED.