Xbox1S locks-up/freezes

My son has had an issue with his Xbox One S freezing and it now has gotten worse to the point, the box is unusable.

Depending on how long the box is on and is allowed to discharge with the power cord detached, it could lock up on:
the green intro screen, the log in screen, a game download, a OSU1 update, a console reset, or when a USB HDD is plugged in or when a bluetooth dongle is present, or just basically whenever it wants to.
Its a slow death. Whatever is going on will stop and some menu navigation will still be present but menu item one by one they will freeze eventually. Usually, you can’t power it down through the menu but when you can, the power light will flash from 10 seconds to forever until you pull the cord.
I’ve redone the thermal paste (which didn’t seem bad) and also looked for damage without seeing any. The only thing consistent with the lockup is when it does freeze, there is always one “chirp” or “buzz” or “BRZZZRREEEDDDTTT” sound from the box if you really listen, almost like rapid HDD head movement. The box does not run hot.
Fortnite is quick sure freeze death. Tempest 4000 has much longer game play life but even in idle splash screen loop mode, eventually that will freeze as well.
It does not turn on and then off and it does not have Exxxx errors like in some other posts.
My latest test was no USBs plugged in, and NO network connectivity. That lasted about an hour and was the longest in recent history.
I’ve read about the mosfets and about the MB traces expanding, etc. I have a new SSD, but I don’t think that will help (probably will return it unopened).
I’m open to ideas, but it seems like the power issues are sure permanent death of these things. Now that I’ve had the case open, does anyone know if MS will fix it for their $159 fee? I’ve read if they see any tampering, they won’t repair it. I’d just buy a used or refurbed one for $220 and get another controller with the deal, but that market has completely dried up. No one has XBOX1S inventory.
Any and all help is welcome. Thx.