Diode identification?

The 0.4Vf likely suggests a SB diode

Yeah, OK, it may well not actually be a diode with Schottky barrier topology. I was using the term in a service engineer's generic way to indicate a high speed fast recovery diode, as opposed to a low speed grunting silicon junction diode - the OP's 'normal' diode that he speaks of.

And yes, being named after German physicist Walter H Schottky, there is a " c " in it ...

I reckon that the key to this one is that it was lightly loaded. A 1N4004 certainly won't stand up to SMPS frequencies for long, if loaded to more than a few tens of mA. In fact I think you were very lucky that it did stand up to it for as long as you say. Even the proper article fail regularly. I change many secondary rectifiers that have failed short circuit in DVD player switchers. Anyway, whatever. I stand by my original reply that the diode will not be a 'standard' silicon one, and the fitting of a standard one would likely result in short order re-failure.

Arfa