Xbox Series S - No Beep, No Power - 1.8v Rail Short?!?!

Hey all. I have an Xbox Series S with no power, no beep. I’ve been testing this thing for days looking for a short (THERE HAS TO BE ONE SOMEWHERE!!) but can’t find anything. Here’s what I’ve discovered so far:

-No caps or components are visibly damaged and none are reading short to ground in continuity mode.

-Tested power rail standby voltage at test points. I get 12v, 5v, and I believe 1.1v. I am missing 1.8v and 3.3v. From my understanding, the 1.8v rail enables the 3.3v.

-Plugged in power supply and felt the board. U446 was getting VERY hot. I replaced with a known-good IC from a One S. IC stopped getting hot. I tested it’s voltage and get the following:

  • Pin1 - VIN - 5.14v
  • Pin2 - GND - 0.0v
  • Pin3 - Shutdown - 4.68v
  • Pin4 - ADJ - 0.01v
  • Pin5 - VOUT - 0.02v

-Amidst my testing, I think I might have damaged U445 - the SB was getting very warm and the speaker would buzz when I plugged in power. I replaced it and both issues went away. I tested U445 and get the following:

  • Pin1 - PG - 4.47v
  • Pin2 - VIN - 5.14v
  • Pin3 - SW - 1.08v
  • Pin4 - PGND - 0.0v
  • Pin5 - OUT - 1.09v
  • Pin6 - AGND - 0.0v
  • Pin7 - FB - 0.6v
  • Pin8 - EN - 4.35v

Clearly there’s a short on the 1.8v rail, but I have absolutely NO clue where to continue looking. I have the schematics and I’m trying to follow em, but it’s not really leading me anywhere.

Helllpppp pleaseeee!

Hello,

I think i too have similar problem but not on 1.8v rail, I’m having partial short on 3.3 volt rail

V_3p3stby test pad reading only 1.1 volt instead of 3.3 volt, I have replaced the IC U54 voltage regulator which is responsible for supplying 3.3 volt, still the issue not solved. The U54 fall backs to low voltage mode when there is short I.e to below 1 volt . I coudnt find where the short around the 3.3 volt rail.

This discord server with name craftbenmine or same name with youtube channel is created to to help repair xbox console. I got schematics and other info from these discord. Hope it will help you find the issue.