As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER TAKEOFF FROM GLH, THE LANDING GEAR TRANSIT LIGHT DID NOT ILLUMINATE WHEN THE GEAR WERE RETRACTED. RAN THE QRH AND THE TRANSIT LIGHT DID WORK WHEN THE GEAR WERE EXTENDED AND GOT THREE GREEN. THE LIGHT DID NOT WORK WHEN THE GEAR WERE RETRACTED AGAIN. LAMPS TEST IS GOOD AND HYDRAULIC PRESSURE WAS NORMAL. REPLACED LANDING GEAR CONTROL UNIT; PN ON AND OFF: D494-12-001; SN ON: 672/05-98; SN OFF: 604/04-96. REF. AMM 32-31-05-02.