As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON GEAR RETRACTION SFO BOTH RED AND GREEN LIGHTS REMAINED ON. NO LIGHTS ON S/O PANEL. RECYCLED WITH ALL GREEN AND NO RED. RETRACTED GEAR A SECOND TIME, SAME RESULTS. THEN 5 TO 8 MINUTES LATER BOTH LIGHTS WENT OUT. MADE UNSCHEDULED LANDING DEN. *S/D* RESISTANCE OF UPLOCK AND DOWNLOCK SENSORS CHECKED OK. REPLACED DOWNLOCK CIRCUIT CARD FOR PRECAUTIONARY REASON. CHECK GOOD ON GEAR SWING.