Rifa Madness

[ArthurDent]

I have replaced a number of the IEC filters in older HP equipment before there was any explosion and mess in the unit they were in. Today I was load testing an HP bench power supply and all of a sudden there was a loud 'snap' and the magic smoke billowed out of the top of the supply

The supply didn't have one of the notorious IEC filters but it did have one of the exploding Rifa capacitor across the line that had popped. Fortunately it wasn't sealed inside a IEC filter or the report would have been much louder. There was no black goo and the power supply will look like new once a replacement capacitor is installed. Here are a couple of photos and you can see how the plastic case has cracked all over and apparently this lets moisture in and eventually the capacitor shorts out. 

[Gyro]

Yes, old Rifa metalized paper cap cracking and moisture ingress failure comes up a lot around here!