As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHEN THE A/C EMERGENCY PWR IN USE LIGHT CAME ON, PER POM THE EMERGENCY PWR SWITCH WAS PLACED TO THE OFF POSITION. THE EMERGENCY AC BUS OFF LIGHT CAME ON INDICATING THE EMERGENCY AC BUS WAS BEING POWERED FROM THE BATTERY. ACFT WAS DIVERTED TO LAS. REPLACED A/C EMERGENCY POWER TRANSFER RELAY R2-47.