As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
STANDBY POWER ANNUNCIATOR LIGHT WON’T GO OUT. INSPECTED ACFT & FOUND THAT THE RETAINING RING FOR THE STANDBY ALTERNATOR DRIVE PULLEY HAD FAILED. DUE TO THIS FAILURE THE DRIVE PULLEY HAD MIGRATED OUT OF THE HOUSING ASSEMBLY & WAS LYING IN THE ENG COWLING ASSEMBLY. THE DRIVE ASSEMBLY WAS REPLACED AS AN ASSEMBLY.