What was found
WHILE ATTEMPTING TO COMPLETE T/C 78273000, INTERROGATED THE FMC CDU FOR ENGINE FAULTS, ENGINE 1 EEC SHOWS WHEN RECENT FAULTS SELECTED "CH B EEC DATA NOT AVAILABLE - CANNOT ACCESS CH B". ACFT GROUNDED. WILL NOT ENTER INTO GROUND TESTS WHEN LINE 4L SELECTED. IDENT/ CONFIG SHOWS SAME FAULT. CYCLED A/C POWER AND CYCLED 4 EA, C/B'S P18-2 A1, A3, A4, AND A5, NO HELP. REPLACED NR 1 EEC REF MM 73-21- 60. OPS NORMAL, REF SAME MM REQ'D TESTS.