Related to this post, we'll go over how set an LBD instance in to and out of maintenance mode. This can be done from the desktop of any AOS in the cluster. Below are examples of what is required. The paths in your instance will be different and it will be different for every deployment. To get the values, open task manager, click on the details tab, find AXService.exe, right click then go to "Open File Location". Use that to replace all of the paths in the examples below to get a command that will work in your specific environments.

Turn On Maintenance Mode 

C:\ProgramData\SF\AOS_233\Fabric\work\Applications\AXSFType_App91\AXSF.Code.1.0.20180423002528\Bin\Microsoft.Dynamics.AX.Deployment.Setup.exe --metadatadir C:\ProgramData\SF\AOS_233\Fabric\work\Applications\AXSFType_App91\AXSF.Code.1.0.20180423002528\Packages --bindir C:\ProgramData\SF\AOS_233\Fabric\work\Applications\AXSFType_App91\AXSF.Code.1.0.20180423002528\Bin --sqlserver full.fqdn.domain.com --sqldatabase axdbtest --sqluser axdbadmin --sqlpwd  **** --setupmode maintenancemode --isinmaintenancemode true

Turn Off Maintenance Mode

C:\ProgramData\SF\AOS_233\Fabric\work\Applications\AXSFType_App91\AXSF.Code.1.0.20180423002528\Bin\Microsoft.Dynamics.AX.Deployment.Setup.exe --metadatadir C:\ProgramData\SF\AOS_233\Fabric\work\Applications\AXSFType_App91\AXSF.Code.1.0.20180423002528\Packages --bindir C:\ProgramData\SF\AOS_233\Fabric\work\Applications\AXSFType_App91\AXSF.Code.1.0.20180423002528\Bin --sqlserver full.fqdn.domain.com --sqldatabase axdbtest --sqluser axdbadmin --sqlpwd **** --setupmode maintenancemode --isinmaintenancemode false