On A+ in a dark setting, the flash should fire. If it doesn't and the flash is raised to shooting position, then you likely have a malfunctioning camera and should contact Canon for servicing. The built-in flash does not automatically pop up--which I love by the way--and you have to raise it manually.
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Digital via Canon R100 and R8. Analog via Pentax, Nikon, and Minolta 35mm SLRs and via Mamiya RB67 and 645, not to mention the persnickety Pentax 17.
