As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER TAKE OFF GEAR RETRACTED NORMAL ON AFTER T/O FLOW WHEN PUT GEAR HANDLE TO OFF, ALL RED AND GREEN LIGHTS ILLUMINATED AND SOUNDED LIKE ALL GEAR EXTENDED. FOLLOWED QRH AND GEAR RETRACTED ALL LIGHTS OUT. PERFORMED OPERATIONAL TEST OF LANDING GEAR, PER B737 AMM 32-32. OPERATIONS CHECK OK.