What was found
(CAN) DURING APPROACH, ANTI-SKID INOP ANNUNC ILLUM. EMERG SYS WAS UTILIZED FOR FINAL BRAKING. ILLUM OF ANTI-SKID ANNUNC, NORMAL BRAKING, ANTI-SKID OR POWER BRAKES ARE BLOCKED, ARE NOT AVAILABLE BY DESIGN. EMER BRAKING MUST BE UTILIZED. A/C WAS RETURNING FROM TRIP ENCOUNTERING RAINS AND CONDENSATION. NOT VERIFIED AS TO WAS ANTI-SKID INOP ANNUNC ILLUMIN AS FAULT COULD NOT BE REPEATED MOISTURE COULD BE POSSIBILITY. POWER BRAKE SYS INCLUDING ANTI-SKID PORTION WAS CHECKED FOR FUNCTION AND BLED. DURING MAINT, AIR IN BRAKING SYS, PRECHARGE VALUE ON ACCUM WAS LOWER THAN SPECIFIED. POSSIBLE THAT AIR IN SYS PROVIDED FEEDBACK TO DIGITAL ANTI-SKID MONTIORING SYSTEM, IND SYS FAULT, DISABLING NORMAL POWERBRAKING.