As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
BEFORE PUSHBACK THE CREW NOTICED A LARGE AMOUNT OF SMOKE IN THE CABIN WHILE THE AIRPLANE WAS PARKED. THEY DEPLANED THE PASSENGERS AND CALLED MAINTENANCE CONTROL. REMOVED AND REPLACED RH ACM IAW AMM 21-51-08-000/400-801-A01 OPS CHECKS GOOD.