As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLIGHT 4536 PIT-HGR. JUST AFTER TAKE-OFF FROM PIT DURING CLIMB THE MAIN INVERTER FAIL LIGHT ILLUMINATED. CREW FOLLOWED QRH AND SWITCHED TO THE STANDBY INVERTER. TRANSFER WAS GOOD WITH NO SYSTEM FAILS. A/C TURNED AROUND AND RETURNED TO GATE AT PIT. A/C WAS TAKEN OUT OF SERVICE.