Cleaning out what I thought was a standard "Trinity" model slim and find this oddity, it is not a dev unit and appears to be a stock machine. : r/ xbox360
The Xbox 360 Chipset - Inside Microsoft's Xbox 360
Xbox 360 Southbridge Reballing - YouTube
South Bridge Chip KSB X850744-002/004 45nm for Microsoft Xbox360 Slim (Reballed)--X360 E/Slim Repair Parts | Westingames.com
Amazon.com: Xbox 360 RAM Heatsinks (4 pcs) for HANA ANA Southbridge RAM Chips - Upgrade Cooling Repair - Prevent RROD : Video Games
The Motherboard - Welcome to Valhalla: Inside the New 250GB Xbox 360 Slim