What was found
UPON REACHING FL390 THE CABIN DOOR ANNUNCIATOR ILLUMINATED. ALL GREEN FLAGS WERE VISIBLE AND NO OTHER WARNING LIGHTS (SIX PACK) WERE ILLUMINATED.///SIGN-OFF///REMOVED MAIN CABIN DOOR STEPS PER CE-560XL MM 52-10-02. OPERATED MAIN CABIN DOOR WITH NO FAULTS FOUND. SHOOK DOWN WIRING AND FROZE SWITCHES. NO FAULTS FOUND. REMOVED AND REPLACED CABIN DOOR MONITOR PCB PER CE-560XL MM 24-51-02-2. MAIN CABIN DOOR INDICATION OPS CHECKS GOOD PER CE-560XL MM 52-70-00-2. REINSTALLED MAIN CABIN DOOR STEPS PER CE-560XL MM 52-10-02.