As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON APPLICATION OF T/O POWER RT ENG TRIPPED OFF LINE WITH EICAS MSG. SAMC TEXT: CREW REPORTS THAT RT IDG FREQ FLUCTUATES BETWEEN 419 TO 420 HZ AND THEN GOES BLANK AT IDLE. REPLACED RT GEN CONTROL UNIT IAW MM. ALSO ADJ IDG FREQUENCY 5 TURNS CW EQUAL TO 15 HZ, OP UT NOW READS 398 HZ IAW MM. ALL OPS NORMAL.