What was found
(CAN) #2 ENGINE HIGH VIBRATION INDICATION OF 4.0 UNITS DURING CLIMB. NON NORMAL CHECKLIST COMPLETED AND THRUST REDUCED TO 88% N1, VIBES AT 3.9 UNITS. LEVELED OUT AT FL320 WITH N1 AT 83%, ENGINE VIBES AT 3.1 UNITS. DIVERTED BACK TO BASE. PRIOR TO THIS OCCURRENCE A BLADE LUBE AND VIBE SURVEY WERE CARRIED OUT. BLADE RE-MAP ALSO CARRIED OUT WITH NO SUCCESS IN REDUCING THE VIBES. SEVERAL MORE VIBE SURVEYS C/O AFTER BLADE MAPPING BUT COULD NOT IMPROVE THE RESULTS. #2 ENGINE WEIGHTS RETURNED TO NOMINAL, FINAL SURVEY C/O IAW AMM 71-00-00 WITH THE FOLLOWING RESULTS, MAX VIBES 1.7 WITH N1AT 94.5% AND N2 AT 96.5%. C/O TROUBLE SHOOTING OF AVM SYSTEM AND FOUND 0.05 VDC OF STRAY VOLTAGE ON NUMBER ONE BEARING CIRCUITRY. BOEING SERVICE LETTER 737-SL-77-016 C/O AND NUMBER ONE BEARING SENSOR DEACTIVATED. ENGINE OPERATIONAL TEST C/O AND VIBE INDICATION FOUND TO BE SATISFACTORY. (TC# 20190529017)