What was found
LT AC PWR FAULT, LAC BUS OFF, DC BUS OFF. DURING CRUISE LOST ALL LT AC PWR AND LT AC ELECTRICAL FUNCTIONS. AFTER LDG APU GEN PICKED UP LT ELECTRICAL LOAD BUT STILL HAD LT AC PWR FAULT MSG. DIVERTED ABQ. RAN ALL ENGS AND APU, GEN AND CROSSTIE FUNCTIONS OPN NML. PERFORMED BITE ON EPCU, LT CONVERTER FAULT FOR LAST 5 LEGS. REPLACED LT CONVERTER. GEN AND CROSSTIE SYS CKS NML.