As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED: AN EMERGENCY WAS DECLARED AND THE AIRCRAFT RETURNED TO SFO DUE TO THE LANDING GEAR WOUND NOT RETRACT AND SHOCK ABSORBER FAULT. THE AIRCRAFT LANDED AT SFO SAFELY WITHOUT FURTHER INCIDENT. MAINTENANCE REPLACED NOSE GEAR FLIGHT / GROUND SENSING MECHANISM PER AMM 32-31-73 AND ACCOMPLISHED A SATISFACTORY OPERATIONAL CHECK.