[Xbox turns on for a second, turns off, and then on again with an orange blinking light.]

On 4/23/2021 at 4:22 PM, KaosEngineer said:

The System Management Controller (SMC) is detecting an overheating condition.  This can be falsely sent to the SMC by the ADM1032 8-pin surface mount temperature sensor at location U6F1.  If clock cap electrolyte reached the two support caps on the left side or between the pins of the chip, the false reading can be sent.  Or, if the chip has died, another condition that can cause the false overheating signal to be registered by the SMC.

Fix:   Clean the motherboard in and around the chip with cotton swabs and 91%+ isopropyl alcohol.  If that doesn't fix it, unsolder it and replace it with a new one.

https://www.mouser.com/ProductDetail/ON-Semiconductor/ADM1032ARMZ-REEL?qs=t2BMfLoP1KQzRXaQRzFLxA%3D%3D

Wanted to say that I ran into this issue just this past week and this solution worked wonderfully. Bought another chip from Mouser, swapped it out with the original, and everything has been working wonderfully since. 

This was after cleaning the board, replacing the thermal paste, etc. 

Thank you!!