As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE FLIGHT CREW REPORTED THE "HYD 1 LO PRESS" ILLUMINATED AFTER THE FINAL FLAP SETTING AND REMAINED ON. TROUBLESHOOTING FOUND THE NR 1 HYD PRESSURE SWITCH P/N 15185-4SN1 TO BE DEFECTIVE. A NEW SWITCH WAS INSTALLED, FUNCTIONAL CHECKS SATISFACTORY.