As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLT 1404 SFO-AUS, CREW DECLARED EMERGENCY DUE TO PRIOR A/C DESCENT INTO AUS THERE WAS A SMELL OF ELECTRICAL BURNING AROUND 20ABC AREA. F/A'S NEVER SAW SMOKE, HOWEVER SMELL WAS VERY PRESENT. CAPT TURNED OFF OVERHEAD AFT AVIONICS POWER RACK AND SMELL DISSIPATED. LANDED AND TAXIED TO GATE WITHOUT ANY SMELL OF SMOKE (LTV SYS- ALL).