As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DFW - CREW REPORTED "DC BUS OFF" ANNUNCIATOR ILLUMINATED DURING CLIMBOUT. FLIGHT RETURNED DFW LANDED WITHOUT INCIDENT. AIRCRAFT REMOVED FROM SERVICE. REPLACED DIRECT CURRENT EMERGENCY POWER TRANSFER RELAY R2-326. SYSTEM GROUND CHECK NORMAL OPERATION.