All power went out when I turned on ignition. What fuse or cause could this be?

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Checked battery the day before to see voltage for alternator. Everything checked out OK. Next morning went to start car and inserted key, heard audible dinging and normal lights inside but when I turned the key I heard a pop noise and everything went dead. No manual head lights, no interior lights, no dash lights, nothing. Complete power failure. Which fuse would this be and / or what should I check. Can I reset the computer by removing the ground to the battery?? Please help if you know what this might be.