As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
L GEN DRIVE DISC LIGHT FLICKERING ON PUSHBACK AFTER ENGINE STARTA/C RETURNED TO THE GATE (BTB) AND MTX GROUNDED A/C. MTX DEFERRED LH GEN FOR DEPARTURE IAW MEL ABX MEL 24-00-1-1 MEL PROCEDURES C/W A/C DOWNGRADED TO ETOPS 120 PLACARD ROTATED MEL PLACARD INSTALLED MBCB 10-20-26. AND RETURNED A/C TO SERVICE.