I was just in the middle of taking some photos, when my camera went off. I left it for a while, tried again and then it turned on. But the next day it wouldn't turn on at all. I have a spare battery and made sure both were charged, and tried both. I've removed SD card and lens, nothing. Normally when you remove lens or SD card a light flashes (provided battery is in), and that didn't happen. I've checked the battery contacts and they're clean.
My camera is (was?) a Nikon D3200.
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Why won't my camera turn on?