How to blow up a hat diode

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Tonight I was working on the IF alignment of my Silvertone/ctc-15 chassis. It is on the bench, as it has been quite a while now. I have the horizontal output tube and the horizontal oscillator tube removed, and a resistor loading the power supply down to simulate the current draw of the horizontal section and the CRT.

Last night I thought I heard a little snap. Not normal crackling, either. The high voltage isn't running. I couldn't find a source, so I just went on. Tonight there was another little snap. This time I saw a little spark from voltage doubler area of the low voltage power supply. I started beating on power supply parts with my alignment stick. I hit one of the power supply diodes and KA-SNAPPPPPPPPPP!!!!!!!!!!!! . Sparks flew from the connection at one end of the diode and the circuit breaker tripped. Oops . On closer inspection the wire running to the floating 160mfd cap was not soldered. I don't think it had ever been soldered. It wasnt even tinned.

I soldered the wire on and tried to bring it up on the variac, but no dice. I pulled the diode out. Sure enough, It's shorted. I pulled the other one, and it was ok.

I had already redone a lot of soldering in this set. The wave soldering on the boards was typically bad. I redid a lot of it. I also cleaned up several old ugly repairs under the chassis, but I missed this. It had apparently been laying there unsoldered for the last 42 years or so, and working fine.

John