Chosen Solution
Ok so my Xbox 360 Slim just started having this problem when I turn it on it immediately powers off. It does this when I hit the power or eject button. The power brick show an orange light when off but then turns green for about a second when I try to turn if on. It seems like it might be a problem with the flexible power ribbon but I’m not sure. If anyone has a fix for this I would appreciate it.
i would try the power supply on another xbox slim ,just to rule out the power supply. after that my best guess would be the small rf/power pcb behind the faceplate. as you dissamble it to get to this board check the mainboard to look for any obvious burnt or blown chips
