Problem: You can't start AKM SQL Server instance on your server.
Cause: Disk failure, power problems/surge
Resolution: Check the ERRORLOG under MSSQL instance directory. To rebuild the system databases, insert your SQL Server installation media and enter the following command:
NOTE: After this operation, you would need to connect to your AKM instance from SQL Management Studio and attach your databases manually.
start /wait <CD or DVD Drive>\setup.exe /qb INSTANCENAME=MSSQLSERVER REINSTALL=ALL REBUILDDATABASE=1 REINSTALLMODE=omus SAPWD=<NewStrongPassword>
You can find more information on this link:
Always take backups before proceeding with SQL Server installations/repairs.