At a commercial deployment, the customer's equipment room encounters unexpected power-off. After the power supply is recovered, the management network port of the S5300 cannot be pinged through, and the OSM cannot be logged in to. Meanwhile, only the global fault indicator on the front panel lights red. No enclosure ID is displayed on both controller modules. By executing the showsys command in CLI mode, the controller software version but not the product name can be detected. By executing the showallver command, the SES version cannot be detected.