There is a report of someone bricking a GS290 by attempting to relock the bootloader, so I would avoid it! If you do not get a better answer you might start a specific thread as this one is marked solved! 
There is a report of someone bricking a GS290 by attempting to relock the bootloader, so I would avoid it! If you do not get a better answer you might start a specific thread as this one is marked solved!