Pi 3B+ stops working

[Gerymake]

Thanks for such great help! I am definitely, gonna go for the ZERO WH.

[Botspot]

In an last attempt to save your Pi, you can try to bypass the fried onboard regulator with an external 3.3v regulation circuit.

I haven't tried this myself, but this is the type of module I mean:
https://usa.banggood.com/DC-DC-3_3V-3A- ... ehouse=CN

Edit: This specific module would require soldering. With this module, you would hook up the wires to your Pi like this:
On module - - on Pi
"In+" - - - - - - - - +5V
"In-" - - - - - - - - GND
"Out+" - - - - - - - 3.3V
"Out-" - - - - - - - GND

[hippy]

The problem with a dead PMIC is that you would likely have to supply all the other voltages it generates as well. Just connecting 3V3 isn't going to work. Also there's more than one 3V3 supply and we don't know what uses which because there are no full circuit diagrams.

We also don't know the PMIC is fried or simply not playing ball. That could mean having to remove it from the board or do more extensive mods than just connecting alternative supplies.

[davidcoton]

In an last attempt to save your Pi, ...

See my reply to the same suggestion here.
Readers, be cautious when people admit "I haven't tried this myself"