![](https://discuss.tchncs.de/pictrs/image/367855b9-f175-4b68-a9c1-aeeb8c3f8319.png)
Are you sure you replaced the 5v regulator with a pin compatible one?
The tlv75733 is a linear regulator, so if you are giving it more voltage than it was set up for, it will get hot, as it has to soak up the difference.
Does the teensy act the same when powered by USB instead? If not, it's not the tlv.
Edit: the tlv has a thermal shutdown, so the shutdown is a direct result of the overheating.
Follow up edit: https://forum.pjrc.com/index.php?threads/one-component-on-teensy-4-1-gets-very-hot.62255/
I am not sure I like TOS because hair (pike)