As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) ABOUT 6-8 MINUTES BEFORE STARTING AN APPROACH, THE COPILOT NOTICED HIS ALTIMTER WAS ARCING AND SMOKE WAS COVERING THE GLASS. THE CAPTAIN NOTICED THE ALTIMETER CIRCUIT BREAKER WAS TRIPPED. AFTER LANDING WE SHUTOFF THE AVIONICS AND TAXIIED TO THE RAMP. MAINTENANCE INVESTIGATION REVEALED THAT IT WAS AN INTERNAL FAULT WITH THE LIGHTING CIRCUIT OF THE ALTIMETER.