What was found
RNO FLIGHT NR 2255: IN CRUISE, RECEIVED DEICE PRESSURE MASTER CAUTION. PERFORMED THE CHECK LIST AND FOUND THE SECOND SEGMENT INBOARD FROM THE RIGHT WING WAS NOT INFLATING AND THE LIGHT DID NOT ILLUMINATE ON THE OVER HEAD PANEL. FLIGHT WAS DIVERTED. MAINTENANCE FOUND THE NR 2 DDV RECEIVING INTERMITTENT OPEN VOLTAGE OF 14.6V. RANG WIRES FROM NR 2 DDV TO TMU WIRES. CHECK GOOD. REPLACED TMU. GROUND RAN BOOTS FOR 1 HOUR WITH NEW TMU. CDS LOGGED NO FAULTS. AIRCRAFT RETURNED TO SERVICE.