As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER STARTING ENGINES PUTTING GEN 1 ON THEN GEN 2 ON. IT TOOK GEN 1 OFFLINE. TRIED AGAIN BOTH THE SAME RESULT. BOTH TIMES GEN 1 SHOWED VOLTS AND FREQS, BUT NO AMPS. THEN TRIED GEN 2 ON FIRST THEN GEN 1 AND IT WORKED FINE IN FLIGHT ALL VOLT FREQ AND AMP CHECKS WERE NORMAL. GROUNDED - YES. REMOVED AND REPLACED #1 IDG PER B737-800 AMM 24-11-11.