Abstract: Based on the facility experimental records and the flashlamp fault data, ten phenomena of faults are found and they are classified into three categories, trigger failures, electrical insulation failures, and flashlamp explosions. Two distinct kinds of faults are found by further analysis, one leading to the flashlamp failures and the other leading to no flashlamp failures. A flashlamps fault tree is obtained for the shot reliability by analyzing logic relationships among the three categories of faults, disk amplifier subsystems, and the shot reliability, which illustrates the importance of the flashlamp reliability to the shot reliability. Finally, a causeeffect diagram for the faults and techniques indicating diverse causes of the flashlamp fault is presented by analyzing the flashlamp