Well the power supply unit is part of the system.
I mean part of the PS4.
It should be built on a separate segregated board though.
Where the output from it connects to the main circuit board of the PS4.
So with that in mind it should have protection built in for any current spikes, or short circuit protection.
Or any over current protection circuits built into it.
The tell tale sign would be to look where the power that exits the power supply circuit boar to the main PS4 board.
would be any melting or blackening around the connection or plug points.
And using your nose to detect any burning or acrid smells from the points mentioned.
Plus a good visual inspection.
It depends how good sony designed the power board to be honest.
But I would say since its a company known for producing quality products.
The Ps4 will probably work with a new supply board fitted in it.
Just one thing Coty what caused the other board to fail or blow.
Liquid or anything like it, or did it just pop on it`s own ?