As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT NOT GROUNDED: AT LEVEL OFF AT FL370. 15 MIN INTO FLIGHT, THE AUTO FAIL LT ILLUMINATED AND THE ALTN LT DIDNT ILLUMINATE. CABIN WAS DESENDING AT 2000 / MIN AND PSID WAS 8.5 WHEN ALTN SELECTED THE ALTN LT NEVER ILLUMINATED AND PRESS WAS NOT UNDER CONTROL. STILL DESENDING 2000 / MIN. WORKED IN MANUAL MODE. REMOVED AND REPLACED CABIN PRESSURE OUTFLOW VALVE IAW AMM 21-31-03.