What was found
AFTER TAKEOFF BOTH F/O EADI AND EHSI WENT BLACK. QRH HAD NO EFFECT. JUST PRIOR TO GOING BLACK, SAW A DPM FLAG ON THE EADI. REPLACED LT AND RT BATTERIES IAW TASK CARD 243401. P/N 4078-7 LT, S/N OFF M1148, ON J02131 RT, S/N OFF P2128, ON 085585. GROUND RAN AC ADI AND HIS. OPS CHECK GOOD.