What was found
WEATHER RADAR TILT APPEARS MISCALIBRATED. DURING CRUISE AT FL370 AUTO TILT MODE WAS DISPLAYING -2 DEGREES BUT PRODUCED GROUND RETURNS AT 30 MILE RANGE. UPON LANDING RECEIVED "PWS FAIL", "WXR FAIL" AND "RT ATT" ANNUNCIATIONS ON RADAR DISPLAY. GROUNDED - YES. PERFORMED TESTS PER B737-800 AMM 34-43-00-710-802-001 AND AMM 34-43-00-730-802-001, NO DEFECTS NOTED. PRECAUTIONARILY APPLYING MEL 34-15H "AUTOTILT/MULTISCAN INOP". NO MAINTENANCE PROCEDURES.