Exploding capacitors

Thursday Patricia calls me with a very alarmed voice, "Hey, it stinks as if something's burning, and there was a loud pop from the computer cabinet". Hmmm, that doesn't sound good. We shut down all the computers in the cabinet until I come home.


Once the kids are in bed, I unrack the firewall machine, open it up, and yes, there is some smell, but not really bad. While I'm looking at the firewall machine, Tatjana's computer turns itself on spontaneously, a loud pop, and electric smell starts to fill the air. "That must be what Patricia meant when she called me."


Nothing out of the ordinary when I open the case, aside from the smell. However, when I open the power supply, the first thing I see are a two capacitor shells sitting oddly in the corner. Also note, how the leftmost capacitor is starting to bend the pressure relief top upwards.


"What is that furry stuff anyways?". The content of the capacitors. Look at the blast marks on the metal heatsink in the background, and the nicely blackend resistor.


As the capacitor on the right blew up it must have hit something in the powersupply (probably the metal heatsink), which dented the top quite a bit.