As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER ARRIVE A/C, BURNING SMELL ON EXT AC POWER. SWITCHED TO APU GEN. OVERHEAD PANEL LIGHTS FLICKERING AND BURNING SMELL CONTINUED NEAR 1 & 2 BREAKER PANELS. AIRCRAFT REMOVED FROM SERVICE. FOUND LAMP TEST #1 TO NOT BE WORKING AND PBA FLICKERING R&R LAMP DRIVER UNIT IAW AMM 31-41-07 OPS CHECKED GOOD PER AWA SUP 09-037E INSP NOT REQ DUE TO ODORS NOT SUSPECT TO BE EMANATING FROM THE AIR SUPPLY DUCTING.