As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CAPTAINS RADAR SWEEP WOULD RANDOMLY TILT DOWN AND SHOW A GREEN + YELLOW ARC IN SOLID COLOR LIKE THIS, THE INDICATIONS ON THE CAPTAINS AND F/O'S SIDE FOR THE RADAR WERE WX+T -2A IN AUTO F/OS SIDE WAS NORMAL. GROUNDED - YES. PER B737-900 FIM 34-43 TASK 814 PERFORMED WEATHER RADAR SYSTEM OPS CHECK IAW B737-900 AMM 34-43-00-710-802-001. OPS CHECK GOOD. INTERMITTENT FAULT.