What was found
(CAN) NR 1 IDG CAUTION MESSAGE CAME ON DURING TAKEOFF ROLL AND CREW ELECTED TO REJECT TAKEOFF. ON WEEK PRIOR OR(JUNE 5), THE CREW RECEIVED A CAUTION MESSAGE (DURING CRUISE AT 31000 FEET) ON EICAS FOR APPROX 30 SECONDS WITH SYNOPTIC CHANGING FROM GREEN TO YELLOW WHILE THE OUTPUT VOLTAGE REMAINED STEADY. MAINTENANCE CARRIED OUT A VISUAL INSPECTION AND THEN AS THE SNAG REOCCURRED, INITIALLY THE SYSTEM WAS DEFERRED IAW AS MEL PROCEDURE AND IDG WAS REPLACED AT THE SAME NIGHT HOURS SINCE INSTALLATION OF IDG. TT 2555.34 AND 1576 CYCLES ON A 381 DAY PERIOD.