You have several paths that may be interpreted wrong. You should always insert a r (raw string literal) before the path if you use single backslashes in path. You also have a ” sign Before "Visible" which should not be there:
I also think it is better to include the parameter names. If you do it will be easier to get the syntax right and you dont have to use empty strings ("") for optional parameters, you can just leave them out:
arcpy.ManageTileCache_management(in_cache_location=r"H:\FV", manage_mode="RECREATE_ALL_TILES", in_cache_name="Visible", in_datasource=r"H:\FV\MosaicData.gdb\FVImages", tiling_scheme="IMPORT_SCHEME", import_tiling_scheme=r"C:\Path\to\existing\scheme\file",...
You also specify that you want to use a tiling scheme (with "IMPORT_SCHEME") but you leave out the next parameter which is the:
Path to an existing scheme file (.xml) or imported from an existing
image service or map service.
If you want to create a tile caching scheme use tool Generate Tile Cache Tiling Scheme:
Creates a tiling scheme file based on the information from the source
dataset. The tiling scheme file will then be used in the Manage Tile
Cache tool when creating cache tiles.