As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CAPT SIDE RADAR IN AUTO MODE PAINTS WX OR GROUND WITH NO CLOUDS IN SKY. FO SIDE SHOWS NOTHING. IN MANUAL MODE, RADAR APPEARS TO WORK NORMAL BOTH SIDES. GROUNDED - YES. REMOVED AND REPLACED WX RADAR TRANSCEIVER IAW B737-900 AMM 34-43-41/400 AS A PRECAUTION. OPERATIONAL GROUND VERIFICATION TEST IS GOOD.