supertabouret

Hello, When I plug the usb pc cable the board won't start (no light nothing) When I put the connect the lipo the board starts fine(all led show no material errors) then I load the gui 1.3 and it connects com4 fine then click read and nothing shows not values. When I try upload firmware with xload, it says upload failed nothing is written. So I can't upload firmware, i can't read write. Any idea? Is the board broken? Any Safe mode? Hope you faced that problem already.. Hope you can help, Thank you..