1. Please determine whether the crossover and business veneer cannot be started as follows.
   1. The single board cannot start normally on line, the network management display is gray or the network management fails to query the single board information.
   2. Business interruption.
2. Check whether the BIOS version is wrong.
   1. For NGSDH products SSN1GXCSA, SSN1EXCSA, SSN1UXCSA, SSN1UXCSB veneers, check whether the base BIOS before upgrading is version 2.13 and before, and the extended BIOS of the target version is version 2.32 and after.
   2. Verify that the base BIOS software is not loaded first when upgrading.
   3. Try to reload the BIOS software, use the DC tool to create a board-level software loading task, select the basic BIOS of the crossover board to load, refer to the simulation package for the method, activate the crossover board and wait for 5 minutes to check whether the single board is online.
3. Replace the single board spare parts.
4. If it is not a crossover, the business single board can not start, turn to determine whether the business configuration has changed or lost.

The relevant technical information and SDH equipment troubleshooting procedures in this chapter are collected and organized by Shenzhen Optical Transmission Network Technology Company Limited (www.opticaltrans.com), and are reproduced and retained! Our company specializes in the sale of Huawei SDH optical transmission equipment,SDH transmission equipment.