Maybe you're looking at the wrong class. Have you tried Microsoft.Windows.Computer$ instead?
Try to go backwards instead like this:
$Class = Get-SCSMClass -Name system.entity #most parent class
$obj = Get-SCSMObject -Class $Class -Filter "Name -like servername" #make sure to have filter here, or you're gonna wait all night : )
$obj.GetLeastDerivedNonAbstractClass()
This will get you the class of the object.
Try to go backwards instead like this:
$Class = Get-SCSMClass -Name system.entity #most parent class
$obj = Get-SCSMObject -Class $Class -Filter "Name -like servername" #make sure to have filter here, or you're gonna wait all night : )
$obj.GetLeastDerivedNonAbstractClass()
This will get you the class of the object.