If you have searched for "TC58NC6623 MPTool" and found nothing, or downloaded random "SSS6698-BA" tools that don't work, here is why:
Elias spent three nights in the digital underworld of forum threads. He learned the names of his enemies: the controller and its partner, the SSS6698-BA . On a Russian firmware archive ( USBDev.ru ), he found the truth written in a translated warning: "For these controllers, there is practically no mass production tool. Recovery is unlikely." The Ritual of the MPTool tc58nc6623 sss6698-ba mptool
The correct tool naming convention is typically: SSS_MPTool_vX.X.X.X_SSS6698-BA or Toshiba_MPTool_vX.XX_6698_BA If you have searched for "TC58NC6623 MPTool" and