As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
JUST AFTER LEVEL OFF AT FL230, NOTED SMOKE IN THE COCKPIT COMING FROM BEHIND S/O PANEL. SMOKE STOPPED AFTER 2 TO 3 MINUTES. AT THE GATE NOTICED PANEL FLOOR C/B POPPED. FOUND PANEL FLOOR BALLAST M354 MELTED AND CONTROL PANEL FLOOR C/B POPPED. REPLACED BALLAS, OPS CK GOOD.