What was found
ENTERED LIGHT RIME ICING DURING CLIMB OUT & RECEIVED ALL NORMAL ICING ADVISORY MESSAGES & 4 OPEN INSCRIPTIONS IN SWITCHES. APPROXIMATELY 10 SECONDS LATER EICAS INDICATED, WG ANTI-ICE FAIL, CAUTION MESSAGE FOLLOWED SHORTLY BY, ICE COND ANTI-ICE INOPERATIVE WARNING. MESSAGES REMAINED UNTIL EXITING ICING CONDITIONS AT WHICH TIME ALL MESSAGES EXTINGUISHED. COMPLIED WITH AOM VOL 1 PROCEDURES. FOUND TUBING TO RT PRESS REG VLV DISCONNECTED, RECONNECTED IAW AMM 20-10-03, OPERATIONS CHECKED IAW AMM 30-00-00, OPERATIONS CHECKED GOOD.