As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PILOT REPORTED INSTRUMENT PANEL LIGHT DIMMER SWITCH FOR ENGINE INSTRUMENTS SMOKED, DIMMER DOES NOT WORK. MAINTENANCE TROUBLESHOT AND FOUND DIMMABLE PANEL TRANSISTOR AND HEAT SINK FAILED. REPLACED THE DIMMABLE PANEL TRANSISTOR AND HEAT SINK ASSEMBLY, AND REPLACED THE DIMMER ASSEMBLY IAW MM 33-40-02.