What was found
AIRCRAFT WAS GROUNDED: PILOT REPORTS DURING TAXI OUT, SMOKE AND FUMES IN COCKPIT. STOPPED TAXI AND VERIFIED NOT GALLEY AS THE SOURCE. STATUS MESSAGE CAME ON WITH EQUIPMENT COOLING FAN RIGHT. RETURNED TO GATE. MAINTENANCE DETERMINED THE SOURCE FROM EQUIPMENT COOLING SUPPLY FAN FAILED DUE TO SUB-STANDARD BEARING. MAINTENANCE REMOVED AND REPLACED LEFT AND RIGHT EQUIPMENT COOLING FANS WITH IMPROVED BEARING. OPS AND LEAK CHECK GOOD IAW AMM 21-27-03.