As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED: PILOT REPORTS ON APPROACH DFW LEFT SOURCE LIGHT AND DRIVE LIGHT ILLUMINATED, APU STARTED AND POWERED LEFT BUS FOR NORMAL LANDING. MAINTENANCE REMOVED AND REPLACED NO. 1 ENGINE IDG IAW AMM 24-11-11. OPS TEST GOOD. NO LEAKS NOTED.