As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED: AN EMERGENCY WAS DECLARED DUE TO: AFTER ROTATION BOTH PFDS LOST ALL VERTICAL AND LATERAL NAVIGATION; AIRCRAFT RETURN TO AND LANDED SAFELY AT DFW. REMOVED AND REPLACED LEFT (FMC) FLIGHT MANAGEMENT COMPUTER. PER AMM 34-61-02, OPERATIONAL TEST GOOD, NO FAULTS FOUND.