Sounds like moisture build up or a capacitor exploded. Some cards will run fine if one is damaged, others not so much, it will put stress on the rest of the components. I'd turn it off for safe measure, take the shell off and have a look before something bad happens again. Or damage another hardware component.
Yeah i think a capacitor exploded. That rig is hashing but around 20kh less than usual on all cards.
Strange how it is still working okay. I had a look and can see a black mark on the back of the card.
I'll run it for 24 hours and see what happens. I guess i will rma it if more issues since it is not 1 year old yet.