What was found
IN FLIGHT AT FL 300, RECEIVED BAT BUS OFF LIGHT ON OVERHEAD PANEL. ALSO LOST RADIO HEADS, IRU #1 AND AUX, DU 4 RED X. CLOCK FAILED. DURING T/S FOUND RCCB B1-160 INOP & CIRCUIT BREAKER B1-949 IS DEFECTIVE. RCCB B1-160 REPLACED PER AMM 24-50-01-4, C/B B1-949 REPLACED PER SWPM 20-60-01. ACCOMPLISHED EPSU R-T-S TEST PER AMM 24-08-01-5, TEST PASSED.