As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
MHT - FLT 4473 - EMERGENCY LIGHTS WILL NOT STAY ILLUMINATED. AIRCRAFT WAS FERRIED TO LGA FOR REPAIR. MAINTENANCE REMOVED AND REPLACED ALL 5 POWER SUPPLY UNITS (S/N 18232, 17662, 18438, 18325 AND 18600) IAW SAAB MM. OPERATIONAL CHECK WAS SATISFACTORY AND AIRCRAFT WAS RETURNED TO SERVICE. (M)