As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON PREFLIGHT, L1 RED WARNING LIGHT DOES NOT ILLUMINATE WHEN TESTED. BUZZER DOES SOUND. FOUND ASPSU WITH RED LIGHT DISPLAYED ON UNIT POSITION. REMOVED AND REPLACED APSU 70WN AND OPERATION CHECKS GOOD IAW AMM 52-73-18/401. THIS CLEARS DMI, PLACARD REMOVED. NO DMP FOR THIS MEL.