ATX Power Supply, Diode Split?

[Double]

I am trying to diagnose a power supply that stopped working, since the shape is sort of custom and expensive to replace, was hoping to repair. I was looking for a blown cap, and came across this, I have never seen a diode that was severed, what would cause this?

I am attaching the photo, any help is appreciated!

Thanks

[naitek]

that looks like a surge for sure.High amps .
probably a voltage spike ..

thats what happens when too much voltage passes through electronics