Hi!
Okay, so the Xbox won't turn on at all?
First I would check the power supply, measure it and see if it works. If not, then replace the PSU and see how that goes!
Guide: [guide|141301|Xbox Series S Power Supply Replacement - iFixit Repair Guide|new_window=true]
If it's still failing after replacing this, then you might want to check the MOSFET. They are known to fail and it's worth a try to check.
Please let us know if you have any more questions, and let us know how it goes!