Arduino Camera without computer

what causes the camera chip 0706 to work only when connected to a computer?
I use Arduino Mega, SD Memory Card, motion sensors and camera.
The sketch is compiled normally and photos are stored in the card, but with an external power supply system is not working.
Any ideas?...

I suspect wrong cabling, e.g. missing Gnd connection. Can you provide a circuit diagram?

@bombata4, do not cross-post. Do not hijack.

Removed thread referenced this: Motion capture camera sketch only works when connected to computer - Sensors - Arduino Forum

I thank you for the answer.
the reason is not in power, because when I close my usb ports (SOFTWARE) Arduino-it refuses to work the same way. After closing the usb port Arduino board has power.