1. Check the power source. Is the power cable connected? Is the wall outlet working?
2. Check the battery. Is it in date? Is it charged?
3. Check the on/off button. Is it in the on position?
4. If your camera uses a memory card does it have the correct type and is it inserted correctly?
5. If your camera has a lens cover make sure it is open.
6. If you can, try a known good battery and/or a known good power source.
7. If the camera still won’t power on try a restart. Unplug the power cable, remove the battery, press and hold the on/off button for 30 seconds then plug in the power and try powering up again.