As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING GARMIN SELF-TEST, NEITHER THE PILOT OR COPILOTS MSG ANNUNCIATOR ILLUMINATED. ADDITIONALLY, WHEN INDUCING A MSG GENERATING FAULT IN THE GPS, WAS UNABLE TO VIEW THE FAULT WHEN PUSHING THE MSG BUTTON ON THE #2 GPS. ALL LIGHTS WORK WHEN W/U IS HELD, BUT NOT DURING GARMIN SELF-TEST. REPLACED #2 GNS 430 IAW CMM 145MMS-023. MOC SUCCESSFULLY COMPLETED.