As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PILOT REPORTED DURING PRE-FLIGHT, PRE-TAXI CHECKS THAT THE GNS-530W GPS/NAV/COM UNIT WAS INOPERATIVE AND THAT HE SMELLED A SMOKE ODOR. ACFT WAS SHUTDOWN AND MX WAS NOTIFIED. MX INSPECTED AND TROUBLESHOT SYS AND R & R GNS-530W GPS/NAV/COM UNIT WITH SERVICEABLE UNIT IAW FE G600 GNS 530W/430W GMA 347, CHAPTER 2.7.9 AND 4.2/4.3 AND 5.5.1 AND 5.5.3. GNS 530W UNIT SYS FUNCTIONAL AND OPS CHECKED GOOD.