As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON FLIGHT 4776, WHILE ON A GROUND HOLD CREW WENT TO SELECT CROSS BLEED TO OPEN AND RECEIVED A CROSS BLEED FAIL EICAS MESSAGE. SMELLED A BURNING RUBBER TYPE ODOR. CONTRACT MAINTENANCE FOUND CIRCUIT BREAKER POPPED. AIRCRAFT REMOVED FROM SERVICE. REMOVED AND REPLACED CROSS BLEED VALVE IAW EMB 140 AMM 36-10-01. OPERATIONAL CHECK GOOD. NO ODORS DETECTED. AIRCRAFT RETURNED TO SERVICE.